Arterial Calcification in Diabetes Mellitus: Preclinical Models and Translational Implications

Sinomenine ameliorates vascular calcification by inhibiting pyroptosis-related molecules and AEG-1 in chronic kidney disease

BACKGROUNDS

Vascular calcification (VC) is an important factor for mortality in chronic kidney disease (CKD). Sinomenine can suppress atherosclerosis. However, its role in CKD-associated-vascular calcification and mechanisms remain unclear.

METHODS

Sprague-Dawley rats that were fed with high-phosphorus diet and adenine suspension were used to construct the calcification model in CKD. Calcification from rats or cells were analyzed using micro-CT and alizarin red staining. Levels of NLRP-3, Caspase-1, GSDMD and AEG-1 were measured by qPCR, western blotting, and immunohistochemistry. Transfection experiment was used in function study.

RESULTS

CKD rats fed with high-phosphorus diet and adenine suspension increased aortic calcification over time. Micro-CT images revealed the distribution and severity of the calcification, and these lesions were significantly decreased in the Sinomenine (SIN) group. This is similar to the results obtained for the AR staining of translucent samples. Additionally, aortas from CKD rats that were treated with 30 mg/kg/d SIN showed a down-regulation of NLRP3, Caspase-1, GSDMD and AEG-1 expression compared with aortas from CKD rats. Sinomenine exhibited similar inhibitory effects on NLRP3 and Caspase-1 as VX-765 in the aortas of uremic rats and calcified VSMCs. Moreover, VSMC transfected with pc-AEG-1 accelerated the VSMC calcification while transfection with si-AEG-1 ameliorated the calcification. Importantly, sinomenine abolished the VSMC calcification induced by AEG-1 overexpression under the uremia condition.

CONCLUSIONS

Our findings indicated that sinomenine could ameliorate vascular calcification in CKD rats and inhibit hyperphosphatemia-induced calcifying VSMCs via inhibiting pyroptosis-related molecules and AEG-1. Sinomenine might serve as an effective therapeutic agent for CKD-associated vascular calcification.

Predictive value of tibial and coronary artery calcification scores for cardiac and lower extremity events

OBJECTIVE

The extent of calcification in the tibial and coronary arteries predicts major ischemic events. Tibial calcification predicts ischemic events in a manner independent of the degree of associated atherosclerotic occlusive disease, and coronary calcification can improve risk stratification in patients at intermediate risk for cardiovascular disease. We thus assessed the relationship between tibial and coronary calcification, the influence of cardiovascular risk factors on their extent, and their individual predictive value on major adverse limb events (MALEs) and major adverse cardiac events (MACEs).

METHODS

We retrospectively reviewed images and collected the demographic and cardiovascular risk factor data of patients who underwent computed tomography scans of the lower extremities and chest. Calcification in the tibial and coronary arteries were identified and scored using semi-automated methods. A Spearman correlation coefficient was calculated using tibial artery calcification (TAC) and coronary artery calcification (CAC) scores. Ordinal logistic regression and multiple linear regression were performed using cardiovascular and demographic factors as covariates. Log-rank test and Kaplan-Meier estimate were completed to assess MACE- and MALE-free probabilities.

RESULTS

A total of 101 patients were identified who met inclusion criteria. There was a strong correlation (r = 0.76) between CAC and TAC scores. Severe CAC (defined as >400) and severe TAC (defined as >500) scores were both associated with advanced age, male sex, a history of smoking, and diabetes. Renal disease was associated with a high TAC score, but not CAC. An increasing TAC score was associated with increased MACE (P < .0001) and MALEs (P = .039). However, increasing CAC was only associated with increased MACEs (P = .0036).

CONCLUSIONS

We provide data suggesting that TAC and CAC share similar risk factors and are highly correlated. Interestingly, TAC predicts both MACEs and MALEs, whereas CAC is best at predicting coronary, but not lower extremity events. Further studies are needed to understand the contributions of arterial calcification to myocardial and lower extremity ischemia.

Simulating Arterial Stress for Rapid Evaluation of Antivascular Calcification Therapies from Herbal Extracts

Vascular calcification severely disrupts cardiovascular hemodynamics, leading to high rates of morbidity and mortality. Despite their clinical impact, the development of effective treatments remains limited, underscoring an urgent need for efficient and reliable drug screening methods. Vascular smooth muscle cells (VSMCs) are known to play a central role in driving the calcification process, undergoing an osteogenic transition in response to pathological conditions. To mimic this process, we developed a cyclic stretching device that replicates the physiological mechanical stresses experienced by VSMCs during arterial pulsation. This device dramatically accelerates the osteogenic transition of VSMCs, reducing phenotypic switching from 13 days under static conditions to just 4 h. Using this device, we screened 20 herbal extracts for anticalcification properties and identifiedSalvia miltiorrhizaas a candidate with therapeutic potential that inhibits VSMC osteogenic transdifferentiation in vitro. The anticalcification efficacy ofSalvia miltiorrhizawas further validated in a vitamin D-induced rat model of cardiovascular calcification, highlighting its translational potential. This screening platform provides a rapid and physiologically relevant method for evaluating potential antivascular calcification therapies, significantly improving the efficiency of drug discovery for clinical translation.

Danlian-Tongmai formula improves diabetic vascular calcification by regulating CCN3/NOTCH signal axis to inhibit inflammatory reaction

Background

Vascular calcification (VC) commonly occurs in diabetes and is associated with cardiovascular disease incidence and mortality. Currently, there is no drug treatment for VC. The Danlian-Tongmai formula (DLTM) is a traditional Chinese medicine (TCM) prescription used for diabetic VC (DVC), but its mechanisms of action remain unclear. This study aims to elucidate the effects of DLTM on DVC and explore the underlying mechanisms of action.

Methods

Ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) was used to identify the metabolites of DLTM. A DVC rat model was established using streptozotocin (STZ) combined with vitamin D3 (VitD3). The effects of DLTM on DVC were evaluated through alizarin red staining, calcium deposition, and changes in osteogenic and contractile markers. The specific molecular mechanism of DLTM in treating diabetic VC was comprehensively analyzed by transcriptomics, molecular docking and in vivo experimental verification.

Results

We identified 108 major metabolites of DLTM. In vivo, high-dose DLTM significantly alleviated VC in diabetic rats. Transcriptomic analysis showed that DLTM treatment markedly altered the transcriptomic profile of rat aortas, which was associated with regulating the CCN3/NOTCH signaling pathway, promoting vascular smooth muscle contraction, and inhibiting the inflammatory responses. Molecular docking and molecular dynamics simulation demonstrated strong binding interactions between DLTM metabolites and key molecules within the CCN3/NOTCH pathway, including NOTCH1, DLL1, DLL4, hes1, and hey1. In vivo experiments confirmed that DLTM could upregulate CCN3, inhibit the activation of NOTCH signaling ligands DLL1 and downstream transcription factors hes1 and hey1, and reduce the release of inflammatory cytokines IL6, IL1β, and TNFα.

Conclusion

DLTM alleviates DVC by regulating the CCN3/NOTCH signaling axis to inhibit inflammatory responses. Our research provides experimental basis for clinical treatment and drug transformation of diabetic VC.

Medial arterial calcification of the lower limbs in diabetes: Time for awareness? A short narrative review

In patients with diabetes, peripheral arterial disease, particularly below the knee, is associated with medial arterial calcification. This is a frequent and potentially serious complication, affecting all types of diabetes. In recent years, our understanding of the pathophysiology and clinical significance of medial arterial calcification has improved considerably. Here, we offer a short narrative review of the epidemiology, clinical consequences, and pathophysiology of this complication. Now that medial arterial calcification of the lower limbs is better understood, we also focus on the prospect of treatments targeting arterial calcification.

Systematic Review and Network Meta-analysis of Vessel Preparation Techniques With Plain Balloon Angioplasty, Atherectomy, or Intravascular Lithotripsy Before Application of a Drug Coated Balloon to Treat Atherosclerotic Femoropopliteal Disease

OBJECTIVE

To compare one year outcomes after atherectomy, intravascular lithotripsy vs. plain balloon angioplasty before application of drug coated balloons for treating femoropopliteal atherosclerotic disease.

DATA SOURCES

MEDLINE, EMBASE, and Cochrane Library were screened until May 2023 for randomised controlled trials.

REVIEW METHODS

This was a systematic review and network meta-analysis. The inclusion criteria were patients with claudication and those with critical limb threatening ischaemia with lesion characteristics of all lengths, stenosis, calcification, and occlusions. The primary outcome was freedom from target lesion re-intervention at one year. Secondary outcomes were rate of bailout stenting, major amputation, and all cause mortality at one year. Pooled point estimates were calculated with a standard random effects model. Further sensitivity analyses were completed with a mixed treatment Bayesian model. Risk of bias was assessed by the Revised Cochrane Risk of Bias tool 2 (RoB2) and certainty of evidence assessed via the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework.

RESULTS

Four RCTs comprising 549 patients (two studies evaluating directional atherectomy, one evaluating rotational atherectomy, one evaluating intravascular lithotripsy against plain balloon angioplasty) were included. The weighted mean length of femoropopliteal lesions was 103.4 ± 6.67 mm. Results of the mixed treatment Bayesian analysis were consistent with pooled analysis for all outcomes. There were no significant differences in freedom from target lesion revascularisation (GRADE, high) (RoB2, low), major amputation (GRADE, low), or mortality (GRADE, moderate). Bailout stenting rates were significantly reduced with intravascular lithotripsy and atherectomy compared with plain balloon angioplasty (RR 0.25, 95% CI 0.07 - 0.89) (GRADE, moderate) (RoB2, low).

CONCLUSION

This review found that intravascular lithotripsy or atherectomy did not appear to incur a statistically significant advantage in freedom from target lesion revascularisation, major amputation, or mortality rate at one year. There was moderate certainty of evidence that bailout stenting is significantly reduced after vessel preparation with intravascular lithotripsy and atherectomy.

Predicting the risk of coronary artery calcium progression in the general population: insights from the MESA and CARDIA studies

AIM

Coronary artery calcium (CAC) progression is a strong predictor of cardiovascular disease. This study aims to develop and validate a practical tool for predicting individual CAC progression in the general population.

MATERIALS AND METHODS

Data were utilized from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort, comprising 5486 participants (47.3% male, mean ± SD age: 61.9 ± 10.2 years), who were randomly assigned to either a training set or an internal validation set at a 7:3 ratio. Additionally, a separate cohort of 2447 participants (44.6% male, mean ± SD age: 40.4 ± 3.5 years) from the Coronary Artery Risk Development in Young Adults (CARDIA) study served as the external validation set. A nomogram was developed based on a Cox regression model incorporating 10 variables selected by the least absolute shrinkage and selection operator (LASSO) method to predict CAC progression.

RESULTS

From the 61 features considered, 10 key variables were identified: age, male sex, smoking status, waist circumference, systolic blood pressure, fasting glucose, lipid abnormalities, and the use of antihypertensive, glucose-lowering, and lipid-lowering medications. The nomogram demonstrated good discrimination with a C-statistic of 0.682 (95% confidence interval [CI], 0.665-0.699) in the training set and 0.750 (95% CI, 0.729-0.771) in the external validation set. Decision curve analysis further confirmed the nomogram's clinical utility in predicting the risk of CAC progression.

CONCLUSION

Our nomogram offers a practical tool for individualized prediction of CAC progression potentially aiding in the primary prevention of cardiovascular disease in clinical practice. REGISTRATION URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT00005130 (CARDIA), NCT00005487 (MESA).

Diabetic Nephropathy-Associated Impaired Aortic Function Is Not Mediated by Mean Arterial Pressure and Its Determinants

Objective: The study aimed to assess the potential impacts of mean arterial pressure (MAP) and its determinants (cardiac output and systemic vascular resistance) on diabetic nephropathy (DNP)-associated impaired aortic function. Methods: This multi-ethnic study included 115 chronic kidney disease (CKD) patients (67 non-dialysis and 48 dialysis). Six aortic function measures were evaluated by SpygmoCor. The stroke volume was determined by echocardiography. Results: Hypertensive nephropathy (HNP) (53.9%), DNP (32.2%), glomerulonephritis (19.1%), and HIV-associated nephropathy (7.8%) composed the major CKD etiologies. Concurrent HNP and DNP were present in 31.1% of the patients. Participants with compared with those without concurrent HNP and DNP experienced more frequent established cardiovascular disease (43.2% versus 14.9%, p = 0.01), a faster pulse wave velocity (p = 0.001), and smaller total arterial compliance as an indicator of proximal aortic stiffness (p = 0.03). DNP was associated with each aortic function measure (p < 0.001-0.02) independent of potential confounders and MAP, as well as its determinants. HNP was not related to aortic function (p > 0.05 for all relationships). MAP and its determinants did not mediate the potential impact of DNP on aortic function (-4.1-6.4% contribution). Covariates that were associated with impaired aortic function measures included MAP and its determinants (p < 0.001-0.01). Conclusions: Mean or distending arterial pressure and its determinants were associated with impaired aortic function in the overall CKD population. However, these hemodynamic factors did not mediate DNP-associated impaired aortic function. Our results suggest that blood pressure lowering can be anticipated to improve impaired aortic function in the overall CKD population but not when it is solely induced by DNP.

Association between diabetes status and long-term outcomes following open and endovascular repair of infrarenal abdominal aortic aneurysms

OBJECTIVE

Current literature reports conflicting findings regarding the effect of diabetes mellitus (DM) on outcomes of abdominal aortic aneurysm (AAA) repair. In this study we examined the effect of DM and its management on outcomes after open AAA repair (OAR) and endovascular AAA repair (EVAR).

METHODS

We identified all patients undergoing OAR or EVAR for infrarenal AAA between 2003 and 2018 in the Vascular Quality Initiative registry data linked with Medicare claims. We excluded patients with missing DM status. Patients were stratified by their preoperative DM status, and then further stratified by DM management: dietary, noninsulin antidiabetic medications (NIMs), or insulin. Outcomes of interest included 1-year aneurysm sac dynamics, 8-year aneurysm rupture, reintervention, and all-cause mortality. These outcomes were analyzed with the χ2 test, Kaplan-Meier methods, and multivariable Cox regression analyses.

RESULTS

We identified 34,021 EVAR patients and 4127 OAR patients, of whom 20% and 16% had DM, respectively. Of all DM patients, 22% were managed by dietary management, 59% by NIM, and 19% by insulin. After EVAR, DM patients were more likely to have stable sacs, whereas non-DM patients were more likely to have sac regression at 1 year. Compared with non-DM, DM was associated with a significantly lower risk for 8-year rupture in EVAR (EVAR hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.51-0.92). Compared with non-DM, NIM was associated with lower risk of rupture within 8-years for both EVAR and OAR (EVAR HR, 0.64; 95% CI, 0.44-0.94; OAR HR, 0.29; 95% CI, 0.41-0.80), whereas dietary control and insulin had a similar rupture risk compared with non-DM. However, compared with non-DM, DM was associated with a higher risk of 8-year all-cause mortality after EVAR and OAR (DM vs non-DM: EVAR HR, 1.17; 95% CI, 1.11-1.23; OAR HR, 1.16; 95% CI, 1.00-1.36). After further DM management substratification, compared with non-DM, management with NIM and insulin were associated with a higher 8-year mortality in EVAR and OAR (EVAR: NIM HR, 1.12; 95% CI, 1.05-1.20; insulin: HR, 1.40; 95% CI, 1.26-1.55; OAR: NIM HR, 1.27; 95% CI, 1.06-1.54; and insulin: HR, 1.57; 95% CI, 1.15-2.13). Finally, there was a similar risk of reintervention across the DM and non-DM populations for EVAR and OAR.

CONCLUSIONS

DM was associated with a lower adjusted risk of rupture after EVAR as well as OAR in patients managed with NIM. Nevertheless, just as in patients without AAA, preoperative DM was associated with a higher adjusted risk of all-cause mortality. Further study is needed to evaluate for differences in aneurysm-related mortality between DM and non-DM patients, and studies are planned to evaluate the independent effect of NIM on aneurysm-related outcomes.

Early Diagnosis of Subclinical Atherosclerosis in Asymptomatic Type 2 Diabetic Normotensive Menopausal Women: A Global Pulse Wave Velocity Study

Arterial stiffness serves as a cardiovascular disease marker, aiding in the early identification of high-risk patients. We aimed to evaluate the prevalence of arterial stiffness, measured by global pulse wave velocity (gPWV), among diabetic normotensive menopausal women (DPMW) and its correlation with levels of glycosylated hemoglobin (HbA1c). We recruited 641 consecutive DPMW diagnosed with type 2 diabetes over 5 years. The control group (CG) consisted of 300 normotensive, normoglycemic menopausal women. Normal gPWV was defined as a velocity ≤7.1 m/s. We enrolled 641 DPMW with a mean age of 57 ± 12 years. The CG comprised 300 normotensive, normoglycemic postmenopausal women with a mean age of 56 ± 4 years. Among DPMW, 29 (4.5%) exhibited increased gPWV compared with 4 (1.3%) in the CG (p < 0.01). Of the 225 (35.1%) DPMW with HbA1c > 7.5%, 23 (10.2%) had increased gPWV. In contrast, among the 416 (64.9%) DPMW with HbA1c < 7.5%, only 6 (1.4%) had increased gPWV (p < 0.0001). Electrocardiographic (ECG) abnormalities were detected in 208 (32.4%) DPMW, with 11 (5.3%) of them exhibiting increased gPWV (p = 0.6). There was a higher prevalence of increased gPWV in asymptomatic normotensive DPMW, with a significant association between increased gPWV and elevated HbA1c levels. However, there was no correlation between increased gPWV and abnormal ECG findings, despite ECG being the sole test recommended by current guidelines for all diabetic patients. Early detection of elevated HbA1c levels and increased gPWV may identify asymptomatic DPMW at higher cardiovascular risk, highlighting the inadequacy of a simple ECG in assessing cardiovascular risk in this population.

Foot Sole Temperature Correlates with Ankle-Brachial Index, Pulse Wave Velocity, and Arterial Age in Diabetic Patients Without Diagnosis of Peripheral Arterial Disease

Background/Objectives: Some vascular alterations such as peripheral arterial disease (PAD) or arterial stiffness can alter perfusion of the limbs, so we wondered if this is reflected in the temperature of the soles of the feet of diabetic patients who did not have a diagnosis of peripheral arterial disease. Foot sole temperature was correlated with the ankle-brachial index (ABI), carotid-femoral pulse wave velocity (cfPWV), brachial-ankle pulse wave velocity (baPWV), and arterial age. Methods: A total of 175 patients with type 2 diabetes mellitus, without a previous diagnosis of PAD, were recruited. Comorbidities, anthropometry, biochemical analysis results, temperature, ABI, cfPWV, baPWV, and arterial age were recorded. Forty-two temperature records were obtained from the sole of the foot with an FLIR T865 thermal imaging camera. ABI, cfPWV, baPWV, and arterial age were obtained using plethysmographic and oscillometric methods. Statistical analysis was performed with SPSS v.29.0 (correlations and multiple linear regression models). Results: All temperature points analyzed correlated negatively with ABI (p < 0.001) and rho values ranged from -0.168 to -0.210. Likewise, cfPWV, baPWV, and arterial age had similar results, since most temperature records showed low rho values and a negative correlation with these parameters. Four models were developed to explain the variables of interest. Temperature was involved in all of them. The temperature of the first toe was included in the prediction of cfPWV, baPWV, and arterial age. Conclusions: There is an inversely proportional relationship between temperature and ABI, cfPWV, baPWV, and arterial age in diabetic patients without a previous diagnosis of arterial disease. Temperature can be a predictor of these hemodynamic variables.

The Association between Fatty Liver Index and Lower Limb Arterial Calcification in Patients with Type 2 Diabetes Mellitus

Background

Peripheral arterial calcification is a prevalent condition in patients with type 2 diabetes mellitus (T2DM), resulting in lower-limb amputation and reduced life quality. Non-alcoholic fatty liver disease (NAFLD), which can be simply evaluated using the fatty liver index (FLI), is closely associated with T2DM development. In this study, we aimed to explore the relationship between FLI and lower limb arterial calcification (LLAC) in T2DM patients and to reveal the value of T2DM patients with NAFLD in predicting the occurrence of LLAC.

Methods

A total of 77 T2DM patients with LLAC who underwent comprehensive physical and health examinations, serological examinations, as well as lower limb computed tomography imaging at Sun Yat-sen Memorial Hospital of Sun Yat-sen University between January 2018 and January 2019 were enrolled in this study. The FLI was calculated using body mass index, waist circumference, triglycerides, and γ-glutamyl transferase. Additionally, LLAC was evaluated using computed tomography with the Agatston scoring algorithm. The patients were divided into three groups based on their FLI values: Non-liver disease group (FLI <30, n = 29), borderline-liver disease group (30 ≤ FLI < 60, n = 32), and NAFLD group (FLI ≥60, n = 16). Univariate and multivariate binary logistic regression analyses were employed to investigate the association between FLI and LLAC in T2DM patients. Furthermore, differences in LLAC among groups were analyzed using post-hoc multiple comparisons and ordinal logistic regression model analysis.

Results

Univariate and multivariate analyses showed that age and FLI influenced LLAC severity in T2DM patients. Moreover, T2DM patients in the NAFLD group had significantly lower LLAC scores than those in the Non-liver disease group. The correlation analysis showed that FLI was negatively associated with LLAC scores (R = -0.31, p = 0.006), while age was positively associated (R = 0.361, p = 0.001).

Conclusions

Our study revealed an inverse relationship between FLI and the degree of LLAC. This indicates that, based on evidence in the current research, NAFLD may not be reliable as a predictor of LLAC in T2DM patients.

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.

Specificities of primary and secondary prevention of lower extremity artery disease in patients with diabetes mellitus

Diabetes mellitus (DM) is a major risk factor for lower extremity arterial disease (LEAD) and about 20% of symptomatic patients with LEAD have DM. In subjects with DM, LEAD is a cause of morbidity and mortality. DM typically causes complications in the form of macro- and microangiopathy. In these patients, macroangiopathy manifests as atherosclerosis like in non-diabetic patients. However, its course is accelerated due to accompanying risk factors like hyperlipidemia and hypertension, with cumulative effects. Other factors are also relevant such as inflammation, endothelial dysfunction, platelet activation, blood rheological properties, hypercoagulability, and factors stimulating vascular smooth muscle cell proliferation. Additionally, DM is a risk factor for restenosis and amputation. DM is strongly associated with femoral-popliteal and tibial LEAD, which manifests earlier in patients with DM and may progress more rapidly to critical limb ischemia. Diabetic microangiopathy is characterized by arteriolosclerosis and interstitial fibrosis which additionally affects progression and outcomes of angiopathy of lower limbs. Glycemic control particularly decreases microangiopathic complications, while prevention of macrovascular complications requires treatment of accompanying risk factors like hypertension and dyslipidemia.

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.

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.

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.

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.

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.

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.

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.

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.