Arterial calcification: a review of mechanisms, animal models, and the prospects for therapy

Calcinosis Prevalence in Autoimmune Connective Tissue Diseases-A Retrospective Study

Background/Objectives: Calcinosis cutis is the deposition of insoluble calcium salts, which may cause inflammation, ulceration, pain, and restricted joint mobility. It rarely develops in damaged tissues (dystrophic subtype), most frequently in autoimmune connective tissue diseases (CTDs), but there is very limited data on the prevalence. Also, therapy remains an unsolved issue. In this study, we aimed to collect data on the prevalence of calcinosis in CTD patients to highlight that it is a considerable problem. Methods: A retrospective study was conducted in our department to assess the epidemiology of dystrophic calcinosis in CTDs between January 2003 and January 2024. Results: A total of 839 CTD patients were identified, of whom 56 had calcinosis (6.67%). The mean age of the calcinosis patients at diagnosis of underlying CTD was 41.16 ± 19.47 years. The mean time interval from the onset of calcinosis was 5.96 ± 8.62 years. Systemic sclerosis was the most common CTD complicated by calcinosis (n = 22). Conclusions: Our results are comparable to those reported previously in the literature. Although calcinosis is rare in the overall population, it is a present and unsolved problem in CTD patients. Therefore, further studies are needed on the factors involved in the development and progression of calcinosis as well as its treatment.

Bilayer vascular grafts with on-demand NO and H2S release capabilities

Nitric oxide (NO) and hydrogen sulfide (H2S) gasotransmitters exhibit potential therapeutic effects in the cardiovascular system. Herein, biomimicking multilayer structures of biological blood vessels, bilayer small-diameter vascular grafts (SDVGs) with on-demand NO and H2S release capabilities, were designed and fabricated. The keratin-based H2S donor (KTC) with good biocompatibility and high stability was first synthesized and then electrospun with poly (l-lactide-co-caprolactone) (PLCL) to be used as the outer layer of grafts. The electrospun poly (ε-caprolactone) (PCL) mats were aminolyzed and further chelated with copper (II) ions to construct glutathione peroxidase (GPx)-like structural surfaces for the catalytic generation of NO, which acted as the inner layer of grafts. The on-demand release of NO and H2S selectively and synergistically promoted the proliferation and migration of human umbilical vein endothelial cells (HUVECs) while inhibiting the proliferation and migration of human umbilical artery smooth muscle cells (HUASMCs). Dual releases of NO and H2S gasotransmitters could enhance their respective production, resulting in enhanced promotion of HUVECs and inhibition of HUASMCs owing to their combined actions. In addition, the bilayer grafts were conducive to forming endothelial cell layers under flow shear stress. In rat abdominal aorta replacement models, the grafts remained patency for 6 months. These grafts were capable of facilitating rapid endothelialization and alleviating neointimal hyperplasia without obvious injury, inflammation, or thrombosis. More importantly, the grafts were expected to avoid calcification with the degradation of the grafts. Taken together, these bilayer grafts will be greatly promising candidates for SDVGs with rapid endothelialization and anti-calcification properties.

Insights into elastic fiber fragmentation: Mechanisms and treatment of aortic aneurysm in Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutations in fibrillin 1 (FBN1) gene. These mutations result in defects in the skeletal, ocular, and cardiovascular systems. Aortic aneurysm is the leading cause of premature mortality in untreated MFS patients. Elastic fiber fragmentation in the aortic vessel wall is a hallmark of MFS-associated aortic aneurysms. FBN1 mutations result in FBN1 fragments that also contribute to elastic fiber fragmentation. Although recent research has advanced our understanding of MFS, the contribution of elastic fiber fragmentation to the pathogenesis of aneurysm formation remains poorly understood. This review provides a comprehensive overview of the molecular mechanisms of elastic fiber fragmentation and its role in the pathogenesis of aortic aneurysm progression. Increased comprehension of elastic fragmentation has significant clinical implications for developing targeted interventions to block aneurysm progression, which would benefit not only individuals with Marfan syndrome but also other patients with aneurysms. Moreover, this review highlights an overlooked connection between inhibiting aneurysm and the restoration of elastic fibers in the vessel wall with various aneurysm inhibitors, including drugs and chemicals. Investigating the underlying molecular mechanisms could uncover innovative therapeutic strategies to inhibit elastin fragmentation and prevent the progression of aneurysms.

Hippo Pathway Activation in Aged Mesenchymal Stem Cells Contributes to the Dysregulation of Hepatic Inflammation in Aged Mice

Aging is always accompanied by chronic diseases which probably attribute to long-term chronic inflammation in the aging body. Whereas, the mechanism of chronic inflammation in aging body is still obscure. Mesenchymal stem cells (MSCs) are capable of local chemotaxis to sites of inflammation and play a powerful role in immune regulation. Whether degeneration of MSCs in the aging body is associated with unbalanced inflammation is still not clear. In this study, immunosuppressive properties of aged MSCs are found to be repressed. The impaired immunosuppressive function of aged MSCs is associated with lower expression of the Hippo effector Yes-associated protein 1 (YAP1) and its target gene signal transducer and activator of transcription 1 (STAT1). YAP1 regulates the transcription of STAT1 through binding with its promoter. In conclusion, a novel YAP1/STAT1 axis maintaining immunosuppressive function of MSCs is revealed and impairment of this signal pathway in aged MSCs probably resulted in higher inflammation in aged mice liver.

Kalkitoxin attenuates calcification of vascular smooth muscle cells via RUNX-2 signaling pathways

BACKGROUND

Kalkitoxin (KT) is an active lipopeptide isolated from the cyanobacterium Lyngbya majuscula found in the bed of the coral reef. Although KT suppresses cell division and inflammation, KT's mechanism of action in vascular smooth muscle cells (VSMCs) is unidentified. Therefore, our main aim was to investigate the impact of KT on vascular calcification for the treatment of cardiovascular disease.

OBJECTIVES

Using diverse calcification media, we studied the effect of KT on VSMC calcification and the underlying mechanism of this effect.

METHODS

VSMC was isolated from the 6 weeks ICR mice. Then VSMCs were treated with different concentrations of KT to check the cell viability. Alizarin red and von Kossa staining were carried out to examine the calcium deposition on VSMC. Thoracic aorta of 6 weeks mice were taken and treated with different concentrations of KT, and H and E staining was performed. Real-time polymerase chain reaction and western blot were performed to examine KT's effect on VSMC mineralization. Calcium deposition on VSMC was examined with a calcium deposition quantification kit.

RESULTS

Calcium deposition, Alizarin red, and von Kossa staining revealed that KT reduced inorganic phosphate-induced calcification phenotypes. KT also reduced Ca++-induced calcification by inhibiting genes that regulate osteoblast differentiation, such as runt-related transcription factor 2 (RUNX-2), SMAD family member 4, osterix, collagen 1α, and osteopontin. Also, KT repressed Ca2+-induced bone morphogenetic protein 2, RUNX-2, collagen 1α, osteoprotegerin, and smooth muscle actin protein expression. Likewise, Alizarin red and von Kossa staining showed that KT markedly decreased the calcification of ex vivo ring formation in the mouse thoracic aorta.

CONCLUSIONS

This experiment demonstrated that KT decreases vascular calcification and may be developed as a new therapeutic treatment for vascular calcification and arteriosclerosis.

Aged mesenchymal stem cells and inflammation: from pathology to potential therapeutic strategies

Natural ageing of organisms and corresponding age-related diseases result mainly from stem cell ageing and "inflammaging". Mesenchymal stem cells (MSCs) exhibit very high immune-regulating capacity and are promising candidates for immune-related disease treatment. However, the effect of MSC application is not satisfactory for some patients, especially in elderly individuals. With ageing, MSCs undergo many changes, including altered cell population reduction and differentiation ability, reduced migratory and homing capacity and, most important, defective immunosuppression. It is necessary to explore the relationship between the "inflammaging" and aged MSCs to prevent age-related diseases and increase the therapeutic effects of MSCs. In this review, we discuss changes in naturally ageing MSCs mainly from an inflammation perspective and propose some ideas for rejuvenating aged MSCs in future treatments.

Pathophysiology and Clinical Impacts of Chronic Kidney Disease on Coronary Artery Calcification

The global prevalence of chronic kidney disease (CKD) has increased in recent years. Adverse cardiovascular events have become the main cause of life-threatening events in patients with CKD, and vascular calcification is a risk factor for cardiovascular disease. Vascular calcification, especially coronary artery calcification, is more prevalent, severe, rapidly progressive, and harmful in patients with CKD. Some features and risk factors are unique to vascular calcification in patients with CKD; the formation of vascular calcification is not only influenced by the phenotypic transformation of vascular smooth muscle cells, but also by electrolyte and endocrine dysfunction, uremic toxin accumulation, and other novel factors. The study on the mechanism of vascular calcification in patients with renal insufficiency can provide a basis and new target for the prevention and treatment of this disease. This review aims to illustrate the impact of CKD on vascular calcification and to discuss the recent research data on the pathogenesis and factors involved in vascular calcification, mainly focusing on coronary artery calcification, in patients with CKD.

Relationship between Arterial Calcifications on Mammograms and Cardiovascular Events: A Twenty-Three Year Follow-Up Retrospective Cohort Study

PURPOSE

Breast arterial calcifications (BAC) have been associated with cardiovascular diseases. We aimed to examine whether the presence of BAC could predict the development of cardiovascular events in the very long term, as evidence has suggested.

PATIENTS AND METHODS

We conducted a 23-year follow-up retrospective cohort study considering women specifically studied for breast cancer. After reviewing the mammograms of 1759 women, we selected 128 patients with BAC and an equal number of women without BAC.

RESULTS

Women with BAC had higher relative risk (RR) for cardiovascular events, globally 1.66 (95% CI): 1.31-2.10 vs. 0.53 (0.39-0.72), and individually for ischemic heart disease 3.25 (1.53-6.90) vs. 0.85 (0.77-0.94), hypertensive heart disease 2.85 (1.59-5.09) vs. 0.79 (0.69-0.89), valvular heart disease 2.19 (1.28-3.75) vs. 0.83 (0.73-0.94), congestive heart failure 2.06 (1.19-3.56) vs. 0.85 (0.75-0.96), peripheral vascular disease 2.8 (1.42-5.52) vs. 0.85 (0.76-0.94), atrial fibrillation 1.83 (1.09-3.08) vs. 0.86 (0.76-0.98), and lacunar infarction 2.23 (1.21-4.09) vs. 0.86 (0.77-0.96). Cox's multivariate analysis, also considering classical risk factors, indicated that this BAC was significantly and independently associated with survival (both cardiovascular event-free and specific survival; 1.94 (1.38-2.73) and 6.6 (2.4-18.4)).

CONCLUSIONS

Our data confirm the strong association of BAC on mammograms and the development cardiovascular events, but also evidence the association of BAC with cardiovascular event-free and specific survival.

Poisoning by Nierembergia veitchii: Effects on vascular smooth muscle cells in the pathogenesis of enzootic calcinosis

Vascular mineralization is a hallmark of enzootic calcinosis. Histopathological, ultrastructural, and immunohistochemical investigations were performed on the external carotid arteries of seven sheep naturally poisoned by Nierembergia veitchii. Histologically, moderate to marked hyperplasia of the tunica intima was observed without mineralization. The tunica media exhibited mild to severe mineralization and osteochondroid metaplasia. Sheep with enzootic calcinosis showed arterial overexpression of osteopontin and tissue-nonspecific alkaline phosphatase and immunolabeling for osteonectin and osteocalcin in both intima and media layers of the tested arteries. The main ultrastructural finding in the tunica media was a marked phenotypic change of vascular smooth muscle cells from a contractile phenotype (VSMC-C) into a synthetic phenotype (VSMC-S). In the tunica media, VSMC-S produced matrix and extracellular vesicles, forming mineralizable granules associated with arterial mineralization. VSMC-S were also present in the tunica intima, but matrix and extracellular vesicles and mineralization were not observed. The absence of matrix and extracellular vesicles in the intimal hyperplasia, even in the presence of noncollagenous bone proteins, tissue-nonspecific alkaline phosphatase, and vitamin D receptors, reinforces the hypothesis that the presence of matrix and extracellular vesicles are crucial for the development of vascular mineralization in enzootic calcinosis. It is proposed that the two different VSMC-S phenotypes in calcinosis are due to the expression of at least two genetically different types of these cells induced by the action of 1,25(OH)₂D₃.

Management of calcinosis cutis in rheumatic diseases

Calcinosis (hydroxyapatite and calcium phosphate crystal deposition) within the extracellular matrix of the dermis and subcutaneous tissue is a frequent manifestation of adult and pediatric systemic autoimmune rheumatic diseases, specifically systemic sclerosis, dermatomyositis, mixed connective tissue disease and systemic lupus erythematosus. In this article, we review classification of calcinosis, highlight mechanisms that may contribute to the pathogenesis of calcinosis and summarize the evidence evaluating non-pharmacologic and pharmacologic interventions for the treatment of calcinosis.

Breast arterial calcifications as an indicator of atherosclerotic cardiovascular disease: comparative analysis of coronary computed tomography scoring systems and carotid intima-media thickness

BACKGROUND

Breast arterial calcification (BAC) is easily detected and commonly observed on screening mammography. That is more frequent among people with diabetes, and these people are at risk of coronary artery disease. The incidence of BAC increases with advancing age. We aimed to determine whether BAC detected by mammography is associated with the development of coronary atherosclerosis in asymptomatic women. It can help reduce morbidity and mortality secondary to atherosclerotic cardiovascular disease.

METHODS

We included one hundred and eighty women over the age of 40 who underwent mammography screening in this multi-modality study. Mammography evaluated the presence of calcifications, the number of involved arteries, and the distribution. We questioned the patients about cardiovascular risk factors such as hypertension and diabetes. The coronary artery disease severity was assessed according to both Agatston and calcium scores on coronary computed tomography (CT). Besides, the relationship between these scores and correlation with carotid artery intima-media thickness was investigated. We stated mean and standard deviation (SD) for continuous variables and reported frequency distributions and percentages. SPSS software version 25.0 was used to perform the analysis.

RESULTS

Overall, 302 of 3,600 cases were positive for BAC. However, 120 of them could be included in the study by the eligibility criteria of our research. In univariate analysis, age, hyperlipidemia, DM, HT, and smoking history were risk factors that significantly affected BAC development. The impact of age and diabetes were maintained in the logistic regression analysis (P<0.005), while the significant effect of the other variables was vanished (P>0.02). Furthermore, moderate and high BAC scores were correlated with higher coronary atherosclerosis scores.

CONCLUSIONS

BAC may predict an additional risk factor for coronary artery disease, particularly in patients having higher scores. That may be an accurate indicator for subsequent development of coronary arterial calcifications so that it may be possible to reduce morbidity and mortality associated with coronary atherosclerosis.

Association Between Coronary Artery Calcium Score and Bone Mineral Density in Type 2 Diabetes Mellitus with Different Visceral Fat Area

PURPOSE

The relationship between coronary artery calcification and bone mineral density (BMD) in T2DM is still unclear. The aim of this study is to analyze the association between coronary artery calcium score (CACs) and BMD in T2DM with different visceral fat area (VFA), and further to explore the clinical significance of CACs in predicting osteoporosis in T2DM patients.

PATIENTS AND METHODS

A total of 479 T2DM patients aged ≥50 years were included. Agatston was applied to calculate CACs to evaluate the degree of coronary artery calcification. Dual-energy X-ray absorptiometry (DXA) was used to measure BMD. According to VFA, all subjects were divided into VFA <100cm² and VFA ≥100cm² group. Adjusted regression analysis was performed to analyze the association between CACs and BMD. ROC curve was used to analyze the optimal cut-off value of CACs for screening osteoporosis.

RESULTS

The baseline showed that in VFA ≥100cm² group, CACs increased significantly than that in VFA <100cm² group (212.1±195.9 vs 139.3±141.8, p<0.001) and total hip BMD decreased obviously (0.968±0.19 vs 1.021±0.184, p=0.01). After multivariable adjustment, CACs was not significantly associated with BMD in all patients (p>0.05). However, CACs was negatively associated with BMD of total hip and lumbar spine in patients with VFA ≥100cm² (total hip β=-0.087 p=0.01; lumbar spine β=-0.052 p=0.005), but not VFA <100cm². ROC curve analysis showed that the optimal cut-off value of CACs for screening osteoporosis was 191.505.

CONCLUSION

The present study implied that associations between CACs and BMD varied by the visceral fat deposition. It is critical to evaluate the condition of visceral fat accumulation for exploring the complex interplay of coronary artery calcification and BMD in T2DM patients. It may be of some clinical value for CACs in predicting osteoporosis in T2DM with visceral obesity.

Systemic immune-inflammation index as a tool for predicting the need for a permanent pacemaker in patients with drug-induced atrioventricular block

BACKGROUND

Drug-induced atrioventricular block (AVB) is generally considered reversible and does not require a permanent pacemaker implantation (PPM). However, some studies have demonstrated a failure of AVB cessation even when the inducing agent has been discontinued. This study has investigated the use of systemic immune-inflammation index (SII) to predict irreversible drug-induced AVB after drug discontinuation.

METHOD

Files of patients with high-degree AVB that required a temporary pacemaker (TPM) were retrospectively analyzed. Sixty-three patients in which AVB was drug-induced were included in the study. The patients were divided into the following two groups: (1) those whose AVB reversed after discontinuation of the related drug, and (2) those in which AVB did not reverse.

RESULTS

AVB reversed in 24 patients (38%) after the inducing agent was discontinued while in the remaining 39 patients (62%) PPM was required. The most common drugs to induce AVB were beta-blockers (n = 46, 73%). Follow-up time with TPM was significantly longer in the irreversible group (2.91 ± 1.05 days vs. 4.94 ± 2.15 days, p < .001). Multivariate logistic regression analysis showed that SII (odds ratio [OR] = 1.002; 95% confidence interval [CI] = 1.000-1.003; p = .01) was an independent predictor of the requirement for a PPM. An SII > 752.05 was found to be a predictor of irreversible AVB requiring PPM with a sensitivity of 64% and specificity of 75% (receiving-operating characteristics [ROC] area under the ROC curve [AUC]: 0.704, 95% CI = 0.570-0.838, p = .007).

CONCLUSION

Approximately 2/3 of drug-induced high-degree AVBs are irreversible. SII is an easily available and cheap inflammatory biomarker that can be used to predict irreversible AVB.

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

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

Association of cystatin C with coronary artery calcification in patients undergoing multidetector computed tomography

Cystatin C is associated with atherosclerosis, but the relationship between cystatin C and coronary artery calcification (CAC) is uncertain. The purpose of this study was to evaluate the predictive value of cystatin C on the occurrence and severity of CAC.A total of 1447 hospitalized patients with coronary computed tomography angiography were selected in this study. According to the CAC score (CACS), patients were divided into calcification group (with CAC, n = 749) and control group (without CAC, n = 698). The calcification group was further divided into low calcification group (CACS < 100, n = 407), medium calcification group (CACS 100-400, n = 203), and high calcification group (CACS≥400, n = 139).Patients with CAC had higher cystatin C level than those in control group (P < .05). With the increase of calcification score, the cystatin C level showed an upward trend. The cystatin C level in the high calcification group was significantly higher than those in the low and medium calcification group (P < .05). ROC curve analysis showed that cystatin C had a high predictive value for the occurrence of CAC [area under the curve 0.640, 95% confidence interval (95% CI) 0.591-0.690, cut-off value 0.945 mg/L, sensitivity 0.683, specificity 0.558, P < .05] and severe CAC (area under the curve 0.638, 95% CI 0.550-0.762, cut-off value 0.965 mg/L, sensitivity 0.865, specificity 0.398, P < .05). Multivariate logistic regression analysis showed that cystatin C was an independent predictor of severe CAC (AOR 3.748, 95% CI 1.138-10.044, P < .05).Cystatin C was significantly associated with the occurrence and severity of CAC, suggesting that cystatin C had the potential as a predictor of CAC.

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.

Association of Zinc Deficiency with Development of CVD Events in Patients with CKD

Deficiency of the micronutrient zinc is common in patients with chronic kidney disease (CKD). The aim of this review is to summarize evidence presented in literature for consolidation of current knowledge regarding zinc status in CKD patients, including those undergoing hemodialysis. Zinc deficiency is known to be associated with various risk factors for cardiovascular disease (CVD), such as increased blood pressure, dyslipidemia, type 2 diabetes mellitus, inflammation, and oxidative stress. Zinc may protect against phosphate-induced arterial calcification by suppressing activation of nuclear factor kappa light chain enhancer of activated B. Serum zinc levels have been shown to be positively correlated with T₅₀ (shorter T₅₀ indicates higher calcification propensity) in patients with type 2 diabetes mellitus as well as those with CKD. Additionally, higher intake of dietary zinc was associated with a lower risk of severe abdominal aortic calcification. In hemodialysis patients, the beneficial effects of zinc supplementation in relation to serum zinc and oxidative stress levels was demonstrated in a meta-analysis of 15 randomized controlled trials. Thus, evidence presented supports important roles of zinc regarding antioxidative stress and suppression of calcification and indicates that zinc intake/supplementation may help to ameliorate CVD risk factors in CKD patients.

[Calcification and atherosclerosis of the coronary arteries]

Calcification is a very common phenomenon in the coronary arteries, which is part of the atherosclerotic process, and the degree of calcification can predict clinical outcomes in patients at high risk of coronary events. Both the degree of calcification and the patterns of its distribution are of prognostic importance, but the relationship of coronary artery calcification with atherosclerotic plaque instability is extremely complex and not fully understood. This article is devoted to the study of calcification markers and their influence on the development of atherosclerotic foci.

Association between Serum Zinc and Calcification Propensity (T50) in Patients with Type 2 Diabetes Mellitus and In Vitro Effect of Exogenous Zinc on T50

Zinc inhibits vascular calcification in vivo and in vitro. Patients with type 2 diabetes mellitus show hypozincemia and are at an elevated risk of cardiovascular events. Recently, an in vitro test (T₅₀-test) was developed for determination of serum calcification propensity and a shorter T₅₀ means a higher calcification propensity. This cross-sectional study investigated the association between serum zinc and T₅₀ in 132 type 2 diabetes mellitus patients with various kidney functions. Furthermore, the effect of exogenous zinc on T₅₀ was also investigated in vitro using separately pooled serum samples obtained from healthy volunteers and patients with hemodialysis. We measured T₅₀ levels using the established nephelometric method. The median (interquartile range) levels of T₅₀ and serum zinc were 306 (269 to 332) min, and 80.0 (70.1 to 89.8) µg/dL, respectively. Serum zinc level showed a weak, but positive correlation with T₅₀ (r_s = 0.219, p = 0.012). This association remained significant in multivariable-adjusted analysis, and was independent of known factors including phosphate, calcium, and magnesium. Kidney function and glycemic control were not significantly associated with T₅₀. Finally, in vitro experiments showed that addition of a physiological concentration of exogenous zinc chloride significantly increased serum T₅₀. Our results indicate that serum zinc is an independent factor with a potential role in suppressing calcification propensity in serum.

Fortified phosphorus‑lowering treatment through administration of lanthanum protects against vascular calcification via regulation of FGF23 in chronic kidney disease

Phosphorus reduction can prevent against vascular calcification (VC) in chronic kidney disease (CKD), but the mechanisms underlying its actions remain unclear. The aim of the present study was to determine the effect of a fortified phosphorus-lowing treatment on VC in CKD. Serum levels of creatinine, blood urea nitrogen (BUN), fibroblast growth factor 23 (FGF23), calcium and phosphorus, and the plasma levels of parathyroid hormone (PTH) were determined in an animal model of CKD treated with or without lanthanum. Haematoxylin and eosin (H&E) staining was performed to examine the structure of kidney tissues. Western blot analysis was performed to compare the levels of total- (t-) extracellular signal-related kinase (ERK) and phospho- (p-)ERK among the different experimental groups to investigate the effect of FGF23 on p-ERK expression. In the animal model, administration of adenine increased the serum levels of creatinine, BUN, FGF23 and phosphorus but decreased the serum levels of calcium. In addition, adenine treatment increased the plasma levels of PTH. H&E staining showed that lanthanum treatment did not alter the severity of renal cortex injury. Furthermore, the levels of t-ERK levels did not notably differ between the Adenine-free, Adenine-vehicle and Adenine-lanthanum groups, whereas the levels of p-ERK and aortic calcium in the Adenine-vehicle group were significantly upregulated. In addition, ectopic overexpression of FGF23 increased the levels of p-ERK, Msx2 and Osx in a dose-dependent manner. Furthermore, a total of 48 patients were enrolled in the present study. In the fortified group, the serum levels of FGF23, phosphorus and PTH were significantly reduced, whereas the serum levels of calcium were significantly increased, indicating an enhanced preventative effect in the fortified group. The results of the present study suggest that FGF23 may be used as a therapeutic target in the management and prevention of VC in CKD.

Synthesis and computational studies of highly selective inhibitors of human recombinant tissue non-specific alkaline phosphatase (h-TNAP): A therapeutic target against vascular calcification

In this study, we have discovered small druglike molecules as selective inhibitors of human tissue-nonspecific alkaline phosphatase (h-TNAP), an enzyme critical for the regulation of extracellular matrix calcification. The upregulation of h-TNAP is associated with various pathologies particularly the vascular calcification (VC). Selective inhibition of h-TNAP over h-NPP1 may serve as a useful therapeutic strategy against vascular calcification. A series of novel triazolyl pyrazole derivatives (10a-y) in which thiol bearing triazole moiety as the zinc binding functional group was introduced to a pyrazole based pharmacophore was synthesized and evaluated as potent and selective inhibitors of h-TNAP over h-NPP1. The biological screening against h-TNAP, h-IAP, h-NPP1 and h-NPP3 showed that many of the synthesized compounds are selective inhibitors of TNAP. Particularly, the compounds 10a-h, 10j, 10m-q, 10u, 10w and 10x displayed high potency and complete selectivity towards h-TNAP over h-NPP1. Compound 10q emerged as a highly potent inhibitor (IC₅₀ = 0.16 µM or 160 nM) against h-TNAP with 127-fold increased inhibition compared to levamisole. On the other hand, compound 10e was found to be most selective inhibitor against the tested APs and NPPs (IC₅₀ = 1.59 ± 0.36 µM). Binding sites architecture analysis, molecular-docking and molecular dynamics simulations (MDS), revealed the basis for h-TNAP and h-IAP ligand selectivity as well as selectivity towards h-TNAP over h-NPP1. These newly discovered inhibitors are believed to represent valuable lead structures to further streamline the generation of candidate compounds to target VC.

Biomarkers of vascular calcification in serum

Over the last decades, the association between vascular calcification (VC) and all-cause/cardiovascular mortality, especially in patients with high atherogenic status, such as those with diabetes and/or chronic kidney disease, has been repeatedly highlighted. For over a century, VC has been noted as a passive, degenerative, aging process without any treatment options. However, during the past decades, studies confirmed that mineralization of the arteries is an active, complex process, similar to bone genesis and formation. The main purpose of this review is to provide an update of the existing biomarkers of VC in serum and develop the various pathogenetic mechanisms underlying the calcification process, including the pivotal roles of matrix Gla protein, osteoprotegerin, bone morphogenetic proteins, fetuin-a, fibroblast growth-factor-23, osteocalcin, osteopontin, osteonectin, sclerostin, pyrophosphate, Smads, fibrillin-1 and carbonic anhydrase II.

The biology of vascular calcification

Vascular calcification (VC), characterized by different mineral deposits (i.e., carbonate apatite, whitlockite and hydroxyapatite) accumulating in blood vessels and valves, represents a relevant pathological process for the aging population and a life-threatening complication in acquired and in genetic diseases. Similarly to bone remodeling, VC is an actively regulated process in which many cells and molecules play a pivotal role. This review aims at: (i) describing the role of resident and circulating cells, of the extracellular environment and of positive and negative factors in driving the mineralization process; (ii) detailing the types of VC (i.e., intimal, medial and cardiac valve calcification); (iii) analyzing rare genetic diseases underlining the importance of altered pyrophosphate-dependent regulatory mechanisms; (iv) providing therapeutic options and perspectives.

Role of the Nuclear Lamina in Age-Associated Nuclear Reorganization and Inflammation

Aging is characterized by the gradual loss of tissue function and integrity. Activation of inflammatory responses accelerates the deterioration of cells and tissues. Many studies have shown that alteration of the components of the nuclear lamina is associated with inflammation, both in vivo and in vitro. However, the mechanism by which the nuclear lamina regulates inflammation is largely unknown. Recent studies have suggested that the nuclear lamina regulates both organization of the three-dimensional chromatin structure at the nuclear periphery and global gene expression, such as the expression of inflammatory response genes. Here, we discuss the current updates in the research on nuclear lamina alteration, activation of inflammation, and nuclear reorganization in models of cellular senescence and organismal aging.

Aloe-emodin inhibits osteogenic differentiation and calcification of mouse vascular smooth muscle cells

Vascular calcification increases the risk of morbidity and mortality in patients with cardiovascular diseases, chronic kidney diseases, and diabetes. However, viable therapeutic methods to target vascular calcification are limited. Aloe-emodin (AE), an anthraquinone is a natural compound found in the leaves of Aloe-vera. In this study, we investigated the underlying mechanism of AE in the calcification of vascular smooth muscle cells (VSMCs) and murine thoracic aorta. We demonstrate that AE repressed not only the phenotypes of Ca²⁺ induced calcification but also level of calcium in VSMCs. AE has no effect on cell viability in VSMC cells. Alizarin red, von Kossa stainings and calcium quantification showed that Ca²⁺ induced vascular calcification is significantly decreased by AE in a concentration-dependent manner. In contrast, AE attenuated Ca²⁺ induced calcification through inhibiting osteoblast differentiation genes such as SMAD4, collagen 1α, osteopontin (OPN), Runt-related transcription factor (RUNX-2) and Osterix. AE also suppressed Ca²⁺ induced osteoblast-related protein expression including collagen 1α, bone morphogenic protein 2 (BMP-2), RUNX-2 and smooth muscle actin (SMA). Furthermore, Alizarin red, von Kossa stainings and calcium quantification showed that AE significantly inhibited the calcification of ex vivo ring formation in murine thoracic aorta, and markedly inhibited vitamin D₃ induced medial aorta calcification in vivo. Taken together, our findings suggest that AE may have therapeutic potential for the prevention of vascular calcification program.

Calcinosis in scleroderma

PURPOSE OF REVIEW

To provide an update on the available literature regarding the epidemiology, pathophysiology, diagnosis, and treatment of calcinosis cutis in patients with systemic sclerosis (SSc).

RECENT FINDINGS

We identified observational studies that describe the frequency of calcinosis in SSc and associated clinical features; molecular studies exploring potential pathogenic mechanisms; and case reports and case series describing new diagnostic approaches and treatments.

SUMMARY

Calcinosis cutis is the deposition of insoluble calcium in the skin and subcutaneous tissues. It represents a major clinical problem in patients with SSc affecting at least one quarter of patients. It is associated with longer disease duration, digital ulcers, acro-osteolysis, positive anticentromere antibody, and positive anti-PM/Scl antibody. Although pathogenesis is unknown, there is evidence supporting local trauma, chronic inflammation, vascular hypoxia, and dysregulation of bone matrix proteins as potential mechanisms. Diagnosis can be made clinically or with plain radiography. Several pharmacologic therapies have been tried for calcinosis with variable and modest results, but surgical excision of calcium deposits remains the mainstay of treatment.

Elastolytic activity of cysteine cathepsins K, S, and V promotes vascular calcification

Elastin plays an important role in maintaining blood vessel integrity. Proteolytic degradation of elastin in the vascular system promotes the development of atherosclerosis, including blood vessel calcification. Cysteine cathepsins have been implicated in this process, however, their role in disease progression and associated complications remains unclear. Here, we showed that the degradation of vascular elastin by cathepsins (Cat) K, S, and V directly stimulates the mineralization of elastin and that mineralized insoluble elastin fibers were ~25–30% more resistant to CatK, S, and V degradation when compared to native elastin. Energy dispersive X-ray spectroscopy investigations showed that insoluble elastin predigested by CatK, S, or V displayed an elemental percentage in calcium and phosphate up to 8-fold higher when compared to non-digested elastin. Cathepsin-generated elastin peptides increased the calcification of MOVAS-1 cells acting through the ERK1/2 pathway by 34–36%. We made similar observations when cathepsin-generated elastin peptides were added to ex vivo mouse aorta rings. Altogether, our data suggest that CatK-, S-, and V-mediated elastolysis directly accelerates the mineralization of the vascular matrix by the generation of nucleation points in the elastin matrix and indirectly by elastin-derived peptides stimulating the calcification by vascular smooth muscle cells. Both processes inversely protect against further extracellular matrix degradation.

Association of the Inactive Circulating Matrix Gla Protein with Vitamin K Intake, Calcification, Mortality, and Cardiovascular Disease: A Review

Matrix Gla Protein (MGP), a small Gla vitamin K-dependent protein, is the most powerful natural occurring inhibitor of calcification in the human body. To become biologically active, MGP must undergo vitamin K-dependent carboxylation and phosphorylation. Vitamin K deficiency leads to the inactive uncarboxylated, dephosphorylated form of MGP (dpucMGP). We aimed to review the existing data on the association between circulating dpucMGP and vascular calcification, renal function, mortality, and cardiovascular disease in distinct populations. Moreover, the association between vitamin K supplementation and serum levels of dpucMGP was also reviewed.

Regulation of Vascular Calcification by Growth Hormone-Releasing Hormone and Its Agonists

RATIONALE

Vascular calcification (VC) is a marker of the severity of atherosclerotic disease. Hormones play important roles in regulating calcification; estrogen and parathyroid hormones exert opposing effects, the former alleviating VC and the latter exacerbating it. To date no treatment strategies have been developed to regulate clinical VC.

OBJECTIVE

The objective of this study was to investigate the effect of growth hormone-releasing hormone (GHRH) and its agonist (GHRH-A) on the blocking of VC in a mouse model.

METHODS AND RESULTS

Young adult osteoprotegerin-deficient mice were given daily subcutaneous injections of GHRH-A (MR409) for 4 weeks. Significant reductions in calcification of the aortas of MR409-treated mice were paralleled by markedly lower alkaline phosphatase activity and a dramatic reduction in the expression of transcription factors, including the osteogenic marker gene Runx2 and its downstream factors, osteonectin and osteocalcin. The mechanism of action of GHRH-A was dissected in smooth muscle cells isolated from human and mouse aortas. Calcification of smooth muscle cells induced by osteogenic medium was inhibited in the presence of GHRH or MR409, as evidenced by reduced alkaline phosphatase activity and Runx2 expression. Inhibition of calcification by MR409 was partially reversed by MIA602, a GHRH antagonist, or a GHRH receptor-selective small interfering RNA. Treatment with MR409 induced elevated cytosolic cAMP and its target, protein kinase A which in turn blocked nicotinamide adenine dinucleotide phosphate oxidase activity and reduced production of reactive oxygen species, thus blocking the phosphorylation of nuclear factor κB (p65), a key intermediate in the ligand of receptor activator for nuclear factor-κ B-Runx2/alkaline phosphatase osteogenesis program. A protein kinase A-selective small interfering RNA or the chemical inhibitor H89 abolished these beneficial effects of MR409.

CONCLUSIONS

GHRH-A controls osteogenesis in smooth muscle cells by targeting cross talk between protein kinase A and nuclear factor κB (p65) and through the suppression of reactive oxygen species production that induces the Runx2 gene and alkaline phosphatase. Inflammation-mediated osteogenesis is thereby blocked. GHRH-A may represent a new pharmacological strategy to regulate VC.

Implication of a novel vitamin K dependent protein, GRP/Ucma in the pathophysiological conditions associated with vascular and soft tissue calcification, osteoarthritis, inflammation, and carcinoma

Gla-rich protein (GRP) or unique cartilage matrix-associated protein (Ucma), the newest member of vitamin K dependent proteins, carries exceptionally high number of γ-carboxyglutamic acid (Gla) residues which contributes to its outstanding capacity of binding with calcium in the extracellular environment indicating its potential role as a global calcium modulator. Recent studies demonstrated a critical function of GRP in the regulation of different pathophysiological conditions associated with vascular and soft tissue calcification including cardiovascular diseases, osteoarthritis, inflammation, and skin and breast carcinomas. These findings established an important relationship between γ-carboxylation of GRP and calcification associated disease pathology suggesting a critical role of vitamin K in the pathophysiological features of various health disorders. This review for the first time summarizes all of the updated findings related to the functional activities of GRP in the pathogenesis of several diseases associated with vascular and soft tissue mineralization, osteoarthritis, inflammation, and carcinoma. The outcome of this review will improve the understanding about the role of GRP in the pathogenesis of tissue calcification and its associated health disorders, which should in turn lead to the design of clinical interventions to improve the condition of patients associated with these health disorders.

A Naturally Fluorescent Mgp Transgenic Mouse for Angiogenesis and Glaucoma Longitudinal Studies

Purpose

Our goal was to generate and characterize a new mouse model in which only angiogenesis- and glaucoma-relevant tissues would be naturally fluorescent. The Matrix Gla (MGP) gene is highly expressed in vascular smooth muscle cells (VSMC) and trabecular meshwork (TM). We sought to direct our Mgp-Cre.KI mouse recombinase to VSMC/TM cells to produce their longitudinal fluorescent profiles.

Methods

Homozygous Mgp-Cre.KI mice were crossed with Ai9 homozygous reporter mice harboring a loxP-flanked STOP cassette preventing transcription of a DsRed fluorescent protein (tdTomato). The F1 double-heterozygous (Mgp-tdTomato) was examined by direct fluorescence, whole mount, histology, and fundus photography. Custom-made filters had 554/23 emission and 609/54 exciter nanometer wavelengths. Proof of concept of the model's usefulness was conducted by inducing guided imaging laser burns. Evaluation of a vessel's leakage and proliferation was followed by noninvasive angiography.

Results

The Mgp-tdTomato mouse was viable, fertile, with normal IOP and ERG. Its phenotype exhibited red paws and snout (cartilage expression), which precluded genotyping. A fluorescent red ring was seen at the limbus and confirmed to be TM expression by histology. The entire retinal vasculature was red fluorescent (VSMC) and directly visualized by fundus photography. Laser burns on the Mgp-tdTomato allowed separation of leakiness and neovascularization evaluation parameters.

Conclusions

The availability of a transgenic mouse naturally fluorescent in glaucoma-relevant tissues and retinal vasculature brings the unique opportunity to study a wide spectrum of single and combined glaucomatous conditions in vivo. Moreover, the Mgp-tdTomato mouse provides a new tool to study mechanisms and therapeutics of retinal angiogenesis longitudinally.

Ultrastructural, Elemental and Mineralogical Analysis of Vascular Calcification in Atherosclerosis

Over the past few decades, remarkable progress has been achieved in terms of understanding the molecular and cellular mechanisms of atherosclerotic vascular calcification and the important role of matrix vesicles in initiating and propagating pathologic tissue mineralization has been widely recognized. Despite these recent advances, however, no definitive data are currently available regarding the texture and composition of the minerals that grow in the vessel wall during the course of the disease. Using different electron microscopy imaging and analysis, we demonstrate that vascular cells can produce and secrete more than one type of matrix vesicles which act as sites for initial mineral deposition independently of their structural features. Our results reveal that apatite formation in the atherosclerotic lesions of the human aorta occur through the deposition of amorphous calcium phosphate that matures over time, transforms into crystalline hydroxyapatite, and radiates towards the lumen of the vesicles, finally forming the calcified spherules. Elemental and mineralogical analyses also demonstrate that the presence of mature and stable amorphous calcium phosphate deposits in the affected tissues is linked to the incorporation of magnesium, which probably delay the conversion to the crystalline phase. Though more rarely, the presence of calcium oxalate crystals has been also documented.

Chronic Inflammation: Accelerator of Biological Aging

Biological aging is characterized by a chronic low-grade inflammation level. This chronic phenomenon has been named "inflamm-aging" and is a highly significant risk factor for morbidity and mortality in the older persons. The most common theories of inflamm-aging include redox stress, mitochondrial dysfunction, glycation, deregulation of the immune system, hormonal changes, epigenetic modifications, and dysfunction telomere attrition. Inflamm-aging plays a role in the initiation and progression of age-related diseases such as type II diabetes, Alzheimer's disease, cardiovascular disease, frailty, sarcopenia, osteoporosis, and cancer. This review will cover the identification of pathways that control age-related inflammation across multiple systems and its potential causal role in contributing to adverse health outcomes.

Hydrogen Sulfide Facilitates the Impaired Sensitivity of Carotid Sinus Baroreflex in Rats with Vascular Calcification

Arterial baroreflex is a general mechanism maintaining cardiovascular homeostasis; its sensitivity is reduced in vascular calcification (VC). Hydrogen sulfide (H₂S) treatment facilitates baroreflexive sensitivity in normal and hypertensive rats. Here, we aimed to detect the effect of H₂S on baroreflexive sensitivity in rats with VC. The rat VC model was induced by vitamin D₃ plus nicotine for 4 weeks. The sensitivity of baroreflex was detected by perfusing the isolated carotid sinus. VC was assessed by hematoxylin and eosin (H&E) staining, Ca²⁺ content and alkaline phosphatase (ALP) activity. Protein levels were detected by western blot analysis. Vitamin D₃ plus nicotine induced structural disorder and elevated Ca²⁺ content in the aortic and carotid arterial wall and increased plasma ALP activity. In the calcified aorta and carotid artery, protein levels of contractile phenotype markers of vascular smooth muscle cells (VSMCs) were downregulated and that of osteoblast-like phenotype markers and endoplasmic reticulum stress (ERS) markers were upregulated. NaHS treatment ameliorated the histologic disorder and Ca²⁺ content in the calcified aorta and carotid artery, inhibited the elevated plasma ALP activity, and prevented the transformation of the VSMC phenotype and activation of ERS in rats with VC. Chronic NaHS treatment prevented the impairment of the baroreflex sensitivity and acute NaHS treatment dose-dependently improved the sensitivity in rats with VC. Our results suggested that H₂S could directly facilitate the impairment of baroreflex in rats with VC and ameliorate VC, which might provide new target and strategy for regulation of the baroreflex and therapy of VC.

A single gene connects stiffness in glaucoma and the vascular system

Arterial calcification results in arterial stiffness and higher systolic blood pressure. Arterial calcification is prevented by the high expression of the Matrix-Gla gene (MGP) in the vascular smooth muscle cells (VSMC) of the arteries' tunica media. Originally, MGP, a gene highly expressed in cartilage and VSMC, was found to be one of the top expressed genes in the trabecular meshwork. The creation of an Mgp-lacZ Knock-In mouse and the use of mouse genetics revealed that in the eye, Mgp's abundant expression is localized and restricted to glaucoma-associated tissues from the anterior and posterior segments. In particular, it is specifically expressed in the regions of the trabecular meshwork and of the peripapillary sclera that surrounds the optic nerve. Because stiffness in these tissues would significantly alter outflow facility and biomechanical scleral stress in the optic nerve head (ONH), we propose MGP as a strong candidate for the regulation of stiffness in glaucoma. MGP further illustrates the presence of a common function affecting key glaucomatous parameters in the front and back of the eye, and thus offers the possibility for a sole therapeutic target for the disease.

MicroRNA-32 promotes calcification in vascular smooth muscle cells: Implications as a novel marker for coronary artery calcification

Cardiovascular calcification is one of the most severe outcomes associated with cardiovascular disease and often results in significant morbidity and mortality. Previous reports indicated that epigenomic regulation of microRNAs (miRNAs) might play important roles in vascular smooth muscle cell (VSMC) calcification. Here, we identified potential key miRNAs involved in vascular calcification in vivo and investigated the role of miR-32-5p (miR-32). According to microarray analysis, we observed increased expression of miR-125b, miR-30a, and miR-32 and decreased expression of miR-29a, miR-210, and miR-320 during the progression of vascularcalcification. Additionally, gain- and loss-of-function studies of miR-32 confirmed promotion of VSMC calcification in mice through the enhanced expression of bonemorphogenetic protein-2, runt-related transcription factor-2(RUNX2), osteopontin, and the bone-specific phosphoprotein matrix GLA protein in vitro. Moreover, miR-32 modulated vascularcalcification progression by activating phosphoinositide 3-kinase (PI3K)signaling and increasing RUNX2 expression and phosphorylation by targeting the 3'-untranslated region of phosphatase and tensin homolog Mrna (PTEN) in mouse VSMCs. Furthermore, we detected higher miR-32 levels in plasmafrom patients with coronary artery disease with coronary artery calcification (CAC) as compared with levels observed in non-CAC patients (P = 0.016), further confirming miR-32 as a critical modulator and potential diagnostic marker for CAC.

Susceptiveness of Vitamin K epOxide Reductase Complex Subunit 1 Gene Polymorphism in Essential Hypertension

BACKGROUND

Essential hypertension (EH) is defined as a worldwide public health problem and one of the important risk factors for development of human coronary artery disease. Increased peripheral arterial resistance is one of the distinguishing characteristics of EH. The extracellular deposition of calcium in the arterial wall is defined as vascular calcification, which results in aortic stiffness and elevation of blood pressure. Regulation of vascular calcification is physiologically limited by γ-carboxylated proteins that regulate mineralization. Any deficiencies related to mineralization influence vascular calcification. As a result of vitamin-K deficiency or any problem associated with the vitamin K epOxide reductase complex subunit 1 (VKORC1) gene, Glu cannot be transformed to Gla and calcification initiates in blood vessels, myocardium, and cardiac.

OBJECTIVE

The aim of the study was to investigate the potential association of VKORC1 polymorphisms with the risk of EH.

MATERIALS AND METHODS

There were 100 individuals diagnosed with EH and 100 healthy individuals involved in the study. 3673G/A (rs9923231) and 9041G/A (rs7294) polymorphisms in the VKORC1 gene were determined by the PCR-restriction fragment length polymorphism method.

RESULTS

A significant difference was found between the rs7294 polymorphisms ratios of the case and control groups, but significant differences weren't found in distribution of the rs9923231 alleles. Finally it was determined that the GG genotype provides a 3.97-fold increased risk for EH compared to the AA genotype for the rs7294 polymorphism.

CONCLUSIONS

Our results suggest that the VKORC1 gene rs7294 polymorphism is important for the development of EH.

The Involvement of Notch1-RBP-Jk/Msx2 Signaling Pathway in Aortic Calcification of Diabetic Nephropathy Rats

BACKGROUND

This study explored the changes in expression of vascular smooth muscle cell (VSMC) markers and osteogenic markers, as well as the involvement of Notch1-RBP-Jk/Msx2 pathway in a rat model of diabetic nephropathy (DN) with vascular calcification.

METHODS

A rat model of DN with concomitant vascular calcification was created by intraperitoneal injection of streptozotocin followed by administration of vitamin D3 and nicotine. Biochemical analysis and histological examination of aortic tissue were performed. VSMC markers and osteogenic markers as well as target molecules in Notch1-RBP-Jk/Msx2 were determined by quantitative real-time polymerase chain reaction and immunohistochemical analysis.

RESULTS

Serum calcium and phosphorus levels were significantly increased in model rats as compared to that in normal controls. Diabetic rats with vascular calcification exhibited mineral deposits in aortic intima-media accompanied by decreased expression of VSMC markers and increased expression of osteogenic markers. Notch1, RBP-Jk, Msx2, Jagged1, and N1-ICD were barely expressed in the aortic wall of normal rats. In contrast, these were significantly increased in the model group at all time points (8, 12, and 16 weeks), as compared to that in the normal rats.

CONCLUSION

Activation of the Notch1-RBP-Jk/Msx2 signaling pathway may be involved in the development and progression of vascular calcification in DN.

Osteonectin (SPARC) Expression in Vascular Calcification: In Vitro and Ex Vivo Studies

Osteonectin, also termed SPARC, is a noncollagenous protein of bone matrix. Since there are controversial results regarding its role during the process of vascular calcification, we investigated osteonectin expression in our in vitro calcification model. Rat vascular smooth muscle cells (VSMCs) were challenged with high phosphate (5 mmol/L Pi) and analyzed quantifying calcium levels, through immunohistochemical studies, and studying gene expression. We detected a peak of osteonectin expression at day 7 in cell treated with high phosphate. The time course of calcium deposition, reflected the expression of osteonectin, resulting extensively present at day 7. On the contrary, the expression of the mitotic marker Ki-67 had a peak at day 4, showing no correlation between osteonectin and cell proliferation. Moreover, 7 days was the time point in which Cbfα1/RUNX-2 had its maximal expression. Furthermore, ascorbic acid increased osteonectin expression, supporting a procalcifying role for this protein. Next we decided to study osteonectin expression ex vivo in fetal, adult not calcified, and adult calcific vessels. Immunohistochemical studies demonstrated a spread and strong reactivity in VSMCs of a 20-week fetus, confirming that osteonectin may have a potential role in regulation of mitosis and in cell differentiation. In adult not calcified arteries, osteonectin was constitutively expressed and its levels increased in atherosclerotic and in calcified plaques, where it could have a regulatory role in the calcification process. Our in vitro and ex vivo data show osteonectin expression during the calcification process and suggest its potential role as procalcifying factor.

Direct comparison of regulators of calcification between bone and vessels in humans

Calcification is not only physiologically present in bone but is a main pathophysiological process in vasculature, favouring cardiovascular diseases. Our aim was to investigate changes in the expression of calcification regulators during vascular calcification in bone and vasculature. Levels of gene expression of osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL), osteopontin (OPN), matrix gla protein (MGP), bone sialoprotein (BSP), SMAD6, and runt-related transcription factor 2 (RUNX2) were determined in bone, aorta, and external iliac artery tissue samples of transplant donors. Histological stages of atherosclerosis (AS) in vessels are defined as "no changes", "intima thickening", or "intima calcification". Patients' bone samples were subgrouped accordingly. We demonstrate that in vessels BSP and OPN expression significantly increased during intima thickening and decreased during intima calcification, whereas the expression of regulators of calcification did not significantly change in bone during intima thickening and intima calcification. At the stage of intima thickening, MGP, OPG, and SMAD6 expression and at stage of intima calcification only MGP expression was lower in bone than in vessel. The expression of BSP and RANKL was regulated in opposite ways in bone and vessels, whereas the expression of MGP, OC, RUNX2, and OPN was regulated in a tissue-specific manner. Our study is the first direct comparison of gene expression changes during AS progression in bone and vessels. Our results indicate that changes in the expression of regulators of calcification in the vessel wall as well as in bone occur early in the calcification process, even prior to deposition of calcium/phosphate precipitation.

Lack of Association between Breast Artery Calcification Seen on Mammography and Coronary Artery Disease on Angiography

Objectives:

Some studies have found correlations between the presence of breast artery calcium (BAC) observed on routine mammograms and risk factors for coronary artery disease (CAD). The aim of this study was to investigate whether such calcifications could predict the presence of coronary atherosclerosis.

Methods:

A total of 319 female patients between 50 and 70 years of age, 187 with significant CAD and 132 with angiographically normal coronary arteries, were randomly selected from a computerised database of our central catheterisation laboratory. The patients' mammograms were evaluated independently for the presence of BAC in a blinded fashion by an experienced breast radiologist, and additional clinical data were extracted from clinical charts.

Results:

The women in the CAD group were older (62.5 vs 60.7 years, p=0.05) and had a higher prevalence of hypertension, diabetes mellitus and dyslipidaemia. Although the prevalence of BAC was marginally higher in the CAD group (43.9% vs 37.1 %, p=0.138), this tendency was eliminated after controlling for confounders. Multiple regression analyses indicated that only age above 63 years (odds ratio [OR]=3.0, 95% confidence interval [CI]= 1.8–4.9) and hypertension (OR=2.2, 95% CI= 1.2–4.1), but not angiographic evidence of CAD (OR=1.0,95% CI=0.6–1.6), predict with BAC on mammography.

Conclusions:

Despite correlation with some risk factors For CAD, the presence of BAC does not differentiate between patients with angiographic evidence of CAD and those with angiographically normal coronary arteries.