Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

4-Octyl itaconate inhibits vascular calcification partially via modulation of HMOX-1 signaling

Vascular calcification frequently occurs in patients with chronic conditions such as chronic kidney disease (CKD), diabetes, and hypertension and represents a significant cause of cardiovascular events. Thus, identifying effective therapeutic targets to inhibit the progression of vascular calcification is essential. 4-Octyl itaconate (4-OI), a derivative of itaconate, exhibits anti-inflammatory and antioxidant activity, both of which play an essential role in the progression of vascular calcification. However, the role and molecular mechanisms of 4-OI in vascular calcification have not yet been elucidated. In this study, we investigated the effects of exogenous 4-OI on vascular calcification using vascular smooth muscle cells (VSMCs), arterial rings, and mice. Alizarin red staining and western blot revealed that 4-OI inhibited calcification and osteogenic differentiation of human VSMCs. Similarly, 4-OI inhibited calcification of rat and human arterial rings and VitD3-overloaded mouse aortas. Mechanistically, RNA sequencing analysis revealed that 4-OI treatment is most likely to affect heme oxygenase 1 (HMOX-1) mRNA expression. The study demonstrated that 4-OI treatment increased HMOX-1 mRNA and protein levels, but suppressed inflammation and oxidative stress in VSMCs under osteogenic conditions. Moreover, HMOX-1 knockdown by siRNA or treatment with the HMOX-1 inhibitor ZnPP9 significantly reversed the suppression effect on calcification of VSMCs and aortas of VitD3-overloaded mice by 4-OI. Furthermore, HMOX-1 knockdown by siRNA markedly abrogated the inhibitory effect of 4-OI on inflammation in VSMCs. These findings suggest that 4-OI alleviates vascular calcification and inhibits oxidative stress and inflammation through modulation of HMOX-1, indicating its potential as a therapeutic target for vascular calcification.

Gla-Rich Protein Is Associated with Vascular Calcification, Inflammation, and Mineral Markers in Peritoneal Dialysis Patients

Background/Objectives: Vascular calcification (VC) is a crucial risk factor for cardiovascular diseases (CVD), particularly in chronic kidney disease (CKD) populations. However, the specific relationship between VC and end-stage renal disease (ESRD) patients undergoing peritoneal dialysis (PD) remains to be fully understood. The identification of new biomarkers to improve VC diagnosis and monitoring would significantly impact cardiovascular risk management in these high-risk patients. Gla-rich protein (GRP) is a VC inhibitor and an anti-inflammatory agent and thus is a potential VC marker in CKD. Here we explored the potential role of GRP as a marker for CVD and investigated the impact of VC in 101 PD patients. Methods: Circulating total Gla-rich protein (tGRP) was quantified in serum and in 24 h dialysate samples. VC score (VCS) was determined using the Adragão method. Results: Serum tGRP was negatively associated with VCS, serum calcium (Ca), phosphate (P), and high-sensitivity C-reactive protein (hsCRP), while it was positively associated with magnesium (Mg). A total of 35.6% of PD patients presented with extensive calcifications (VCS ≥ 3), and the lowest tGRP serum levels were present in this group (419.4 ± 198.5 pg/mL). tGRP in the 24 h dialysate was also negatively associated with VCS and with serum Ca and P. Moreover, serum Ca, P, and VCS were identified as independent determinants of serum tGRP levels. Conclusions: The association of serum tGRP with VC, mineral, and inflammation markers reinforces its potential use as a novel VC biomarker in CKD patients undergoing PD.

Understanding Vascular Calcification in Chronic Kidney Disease: Pathogenesis and Therapeutic Implications

Vascular calcification (VC) is a biological phenomenon characterized by an accumulation of calcium and phosphate deposits within the walls of blood vessels causing the loss of elasticity of the arterial walls. VC plays a crucial role in the incidence and progression of chronic kidney disease (CKD), leading to a significant increase in cardiovascular mortality in these patients. Different conditions such as age, sex, dyslipidemia, diabetes, and hypertension are the main risk factors in patients affected by chronic kidney disease. However, VC may occur earlier and faster in these patients if it is associated with new or non-traditional risk factors such as oxidative stress, anemia, and inflammation. In chronic kidney disease, several pathophysiological processes contribute to vascular calcifications, including osteochondrogenic differentiation of vascular cells, hyperphosphatemia and hypercalcemia, and the loss of specific vascular calcification inhibitors including pyrophosphate, fetuin-A, osteoprotegerin, and matrix GLA protein. In this review we discuss the main traditional and non-traditional risk factors that can promote VC in patients with kidney disease. In addition, we provide an overview of the main pathogenetic mechanisms responsible for VC that may be crucial to identify new prevention strategies and possible new therapeutic approaches to reduce cardiovascular risk in patients with kidney disease.

Causal associations between kidney function and aortic valve stenosis: a bidirectional Mendelian randomization analysis

BACKGROUND

Aortic valve stenosis (AVS) is currently the most common heart valve disease. The results of observational studies on the incidence of AVS in the renal dysfunction population are contradictory due to the short follow-up period and different diagnostic criteria, etc. This study aimed to explore the causal relationship between kidney function and AVS using Mendelian randomization (MR) analysis.

METHODS

We acquired summary statistics of estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) from the CKDGen Consortium and a study on AVS from the FinnGen biobank. Univariate and multivariable MR analyses were conducted to evaluate the causal associations. The MR-Egger intercept and MR-PRESSO Global test were applied to assess the pleiotropic effects. The heterogeneity of MR results was tested by Cochran's Q statistic. Moreover, the Bonferroni and FDR corrections were performed for multiple tests.

RESULTS

Genetically predicted decreased eGFR may be associated with a raised risk of AVS (OR = 0.045, p = 1.317e-04 by IVW; OR = 0.002, p = 0.004 by MR-Egger, OR = 0.091, p = 0.057 by WM). The causal association still established after multiple comparisons. Quality control analyses indicated the absence of heterogeneity and pleiotropy in our MR research. In addition, the causality of eGFR and AVS remained significant in multivariable MR analysis after adjusting BMI, hypertension, T2DM, LDL-C, and smoking.

CONCLUSION

Our MR study discovered that reduced eGFR may be a causative risk factor for AVS. In addition, the evidence did not support a significant causal association of AVS on kidney function.

Adenine-induced animal model of chronic kidney disease: current applications and future perspectives

Chronic kidney disease (CKD) with high morbidity and mortality all over the world is characterized by decreased kidney function, a condition which can result from numerous risk factors, including diabetes, hypertension and obesity. Despite significant advances in our understanding of the pathogenesis of CKD, there are still no treatments that can effectively combat CKD, which underscores the urgent need for further study into the pathological mechanisms underlying this condition. In this regard, animal models of CKD are indispensable. This article reviews a widely used animal model of CKD, which is induced by adenine. While a physiologic dose of adenine is beneficial in terms of biological activity, a high dose of adenine is known to induce renal disease in the organism. Following a brief description of the procedure for disease induction by adenine, major mechanisms of adenine-induced CKD are then reviewed, including inflammation, oxidative stress, programmed cell death, metabolic disorders, and fibrillation. Finally, the application and future perspective of this adenine-induced CKD model as a platform for testing the efficacy of a variety of therapeutic approaches is also discussed. Given the simplicity and reproducibility of this animal model, it remains a valuable tool for studying the pathological mechanisms of CKD and identifying therapeutic targets to fight CKD.

Estimated versus measured aortic stiffness: implications of diabetes, chronic kidney disease, sex and height

BACKGROUND

Aortic stiffness is measured by carotid-femoral pulse wave velocity (PWV), but it can also be estimated (ePWV) based on age and brachial mean arterial pressure (MAP). However, diabetes mellitus and/or chronic kidney disease (DM/CKD) may cause more pronounced damage to the arterial wall, changing the pressure and PWV relationship. Furthermore, sex and height could affect PWV through their relationship to the arterial diameter and path length. The aim of the present study was to quantify the extent to which DM/CKD, sex and height affect the validity of ePWV in predicting PWV.

METHODS

This cross-sectional study evaluated PWV in adult participants at high risk of aortic stiffness, using Complior and the second derivative transit time algorithm (PWV 2nd ). PWV 2nd was converted into intersecting tangent PWV (PWV ITc ), and ePWV was calculated using the Reference Values for Arterial Stiffness Collaboration formulas.

RESULTS

Among 825 patients (62% males), the mean age was 60 ± 17 years, 34% had diabetes mellitus, 69% had CKD, and 24% did not have DM/CKD. MAP, ePWV, PWV 2nd , and PWV ITc were, respectively, 96 ± 14 mmHg, 9.8 (8.1-11.8) m/s, 9.5 (7.8-11.9) m/s and 11.3 (8.8-15.9) m/s. There was a significant interaction between DM/CKD, sex, and the predictive value of ePWV. Increasing height lowered the intercept but did not affect the slope of the relationship between estimated and measured PWVs.

CONCLUSION

These findings suggest that the current ePWV equations do not accurately predict PWV in patients with DM/CKD, and that sex and height should also be considered in the future ePWV equations.

Sirt7 protects against vascular calcification via modulation of reactive oxygen species and senescence of vascular smooth muscle cells

Vascular calcification is frequently seen in patients with chronic kidney disease (CKD), and significantly increases cardiovascular mortality and morbidity. Sirt7, a NAD+-dependent histone deacetylases, plays a crucial role in cardiovascular disease. However, the role of Sirt7 in vascular calcification remains largely unknown. Using in vitro and in vivo models of vascular calcification, this study showed that Sirt7 expression was significantly reduced in calcified arteries from mice administered with high dose of vitamin D3 (vD3). We found that knockdown or inhibition of Sirt7 promoted vascular smooth muscle cell (VSMC), aortic ring and vascular calcification in mice, whereas overexpression of Sirt7 had opposite effects. Intriguingly, this protective effect of Sirt7 on vascular calcification is dependent on its deacetylase activity. Unexpectedly, Sirt7 did not alter the osteogenic transition of VSMCs. However, our RNA-seq and subsequent studies demonstrated that knockdown of Sirt7 in VSMCs resulted in increased intracellular reactive oxygen species (ROS) accumulation, and induced an Nrf-2 mediated oxidative stress response. Treatment with the ROS inhibitor N-acetylcysteine (NAC) significantly attenuated the inhibitory effect of Sirt7 on VSMC calcification. Furthermore, we found that knockdown of Sirt7 delayed cell cycle progression and accelerated cellular senescence of VSMCs. Taken together, our results indicate that Sirt7 regulates vascular calcification at least in part through modulation of ROS and cellular senescence of VSMCs. Sirt7 may be a potential therapeutic target for vascular calcification.

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.

Small Charged Molecule-Mediated Fibrillar Mineralization: Implications for Ectopic Calcification

Numerous small biomolecules exist in the human body and play roles in various biological and pathological processes. Small molecules are believed not to induce intrafibrillar mineralization alone. They are required to work in synergy with noncollagenous proteins (NCPs) and their analogs, e.g. polyelectrolytes, for inducing intrafibrillar mineralization, as the polymer-induced liquid-like precursor (PILP) process has been well-documented. In this study, we demonstrate that small charged molecules alone, such as sodium tripolyphosphate, sodium citrate, and (3-aminopropyl) triethoxysilane, could directly mediate fibrillar mineralization. We propose that small charged molecules might be immobilized in collagen fibrils to form the polyelectrolyte-like collagen complex (PLCC) via hydrogen bonds. The PLCC could attract CaP precursors along with calcium and phosphate ions for inducing mineralization without any polyelectrolyte additives. The small charged molecule-mediated mineralization process was evidenced by Cryo-TEM, AFM, SEM, FTIR, ICP-OES, etc., as the PLCC exhibited both characteristic features of collagen fibrils and polyelectrolyte with increased charges, hydrophilicity, and density. This might hint at one mechanism of pathological biomineralization, especially for understanding the ectopic calcification process.

Post-translational modifications in kidney diseases and associated cardiovascular risk

Patients with chronic kidney disease (CKD) are at an increased cardiovascular risk compared with the general population, which is driven, at least in part, by mechanisms that are uniquely associated with kidney disease. In CKD, increased levels of oxidative stress and uraemic retention solutes, including urea and advanced glycation end products, enhance non-enzymatic post-translational modification events, such as protein oxidation, glycation, carbamylation and guanidinylation. Alterations in enzymatic post-translational modifications such as glycosylation, ubiquitination, acetylation and methylation are also detected in CKD. Post-translational modifications can alter the structure and function of proteins and lipoprotein particles, thereby affecting cellular processes. In CKD, evidence suggests that post-translationally modified proteins can contribute to inflammation, oxidative stress and fibrosis, and induce vascular damage or prothrombotic effects, which might contribute to CKD progression and/or increase cardiovascular risk in patients with CKD. Consequently, post-translational protein modifications prevalent in CKD might be useful as diagnostic biomarkers and indicators of disease activity that could be used to guide and evaluate therapeutic interventions, in addition to providing potential novel therapeutic targets.

Characteristics of calcified nodule attributable to culprit lesion in acute coronary syndrome: A systematic review and meta-analysis

The presence of calcified nodule (CN) is a significant characteristic of atherothrombosis in acute coronary syndrome (ACS). However, its characteristics continue to be understudied. This review aimed to further investigate these characteristics. This study found that CN was a distinctive feature of an atheromatous plaque, representing 6.3% of ACS. CN was more common in NSTE-ACS than in STEMI patients (9.4% vs. 6.6%). CN was also chiefly observed in the left anterior descendant artery (48%), followed by the right coronary (40.4%) and left circumflex (14.5%) arteries. Higher prevalence of hypertension (78.8%), diabetes mellitus (50.8%), multivessel disease (71.7%), and kidney disease (26.43%) were noted in CN compared to non-CN patients. CN-associated ACS also 6-fold increased the risk of target lesion revascularization compared to those without CN.

FOXO1 regulates RUNX2 ubiquitination through SMURF2 in calcific aortic valve disease

The prevalence of calcific aortic valve disease (CAVD) remains substantial while there is currently no medical therapy available. Forkhead box O1 (FOXO1) is known to be involved in the pathogenesis of cardiovascular diseases, including vascular calcification and atherosclerosis; however, its specific role in calcific aortic valve disease remains to be elucidated. In this study, we identified FOXO1 significantly down-regulated in the aortic valve interstitial cells (VICs) of calcified aortic valves by investigating clinical specimens and GEO database analysis. FOXO1 silencing or inhibition promoted VICs osteogenic differentiation in vitro and aortic valve calcification in Apoe-/- mice, respectively. We identified that FOXO1 facilitated the ubiquitination and degradation of RUNX2, which process was mainly mediated by SMAD-specific E3 ubiquitin ligase 2 (SMURF2). Our discoveries unveil a heretofore unacknowledged mechanism involving the FOXO1/SMURF2/RUNX2 axis in CAVD, thereby proposing the potential therapeutic utility of FOXO1 or SMURF2 as viable strategies to impede the progression of CAVD.

Development and evaluation of a chronic kidney disease risk prediction model using random forest

This research aims to advance the detection of Chronic Kidney Disease (CKD) through a novel gene-based predictive model, leveraging recent breakthroughs in gene sequencing. We sourced and merged gene expression profiles of CKD-affected renal tissues from the Gene Expression Omnibus (GEO) database, classifying them into two sets for training and validation in a 7:3 ratio. The training set included 141 CKD and 33 non-CKD specimens, while the validation set had 60 and 14, respectively. The disease risk prediction model was constructed using the training dataset, while the validation dataset confirmed the model's identification capabilities. The development of our predictive model began with evaluating differentially expressed genes (DEGs) between the two groups. We isolated six genes using Lasso and random forest (RF) methods-DUSP1, GADD45B, IFI44L, IFI30, ATF3, and LYZ-which are critical in differentiating CKD from non-CKD tissues. We refined our random forest (RF) model through 10-fold cross-validation, repeated five times, to optimize the mtry parameter. The performance of our model was robust, with an average AUC of 0.979 across the folds, translating to a 91.18% accuracy. Validation tests further confirmed its efficacy, with a 94.59% accuracy and an AUC of 0.990. External validation using dataset GSE180394 yielded an AUC of 0.913, 89.83% accuracy, and a sensitivity rate of 0.889, underscoring the model's reliability. In summary, the study identified critical genetic biomarkers and successfully developed a novel disease risk prediction model for CKD. This model can serve as a valuable tool for CKD disease risk assessment and contribute significantly to CKD identification.

Coronary Artery Disease in Patients Undergoing Hemodialysis: A Problem that Sounds the Alarm

Chronic kidney disease (CKD) is affecting more and more individuals over time. The importance of the increased prevalence is enhanced by the close association with the increased risk of poor individual outcomes such as death, fatal and non-fatal cardiovascular (CV) events and progression to end stage kidney disease (ESKD). ESKD requires replacement treatment such as hemodialysis (HD), a particular and complex context that unfortunately has been rarely considered in observational studies in the last few decades. The current perspective of HD as a bridge to kidney transplant requires greater attention from observational and experimental research both in the prevention and treatment of CV events in ESKD patients. We present a narrative review by performing a literature review to extrapolate the most significant articles exploring the CV risk, in particular coronary artery disease (CAD), in ESKD and evaluating possible innovative diagnostic and therapeutic tools in these patients. The risk of CAD increases linearly when the estimated glomerular filtration rate (eGFR) declines and reached the most significant level in ESKD patients. Several diagnostic techniques have been evaluated to predict CAD in ESKD such as laboratory tests (Troponin-T, N-terminal pro b-type natriuretic peptide, alkaline phosphatase), echocardiography and imaging techniques for vascular calcifications evaluation. Similarly, treatment is based on lifestyle changes, medical therapy and invasive techniques such as coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). Unfortunately in the literature there are no clear indications of the usefulness and validity of biomarkers and possible treatments in ESKD patients. Considering the ESKD weight in terms of prevalence and costs it is necessary to implement clinical research in order to develop prognostic reliable biomarkers for CV and CAD risk prediction, in patients with ESKD. It should be highlighted that HD is a peculiar setting that offers the opportunity to implement research and facilitates patient monitoring by favoring the design of clinical trials.

Multi-Omic Analysis Reveals Genetic Determinants and Therapeutic Targets of Chronic Kidney Disease and Kidney Function

Chronic kidney disease (CKD) presents a significant global health challenge, characterized by complex pathophysiology. This study utilized a multi-omic approach, integrating genomic data from the CKDGen consortium alongside transcriptomic, metabolomic, and proteomic data to elucidate the genetic underpinnings and identify therapeutic targets for CKD and kidney function. We employed a range of analytical methods including cross-tissue transcriptome-wide association studies (TWASs), Mendelian randomization (MR), summary-based MR (SMR), and molecular docking. These analyses collectively identified 146 cross-tissue genetic associations with CKD and kidney function. Key Golgi apparatus-related genes (GARGs) and 41 potential drug targets were highlighted, with MAP3K11 emerging as a significant gene from the TWAS and MR data, underscoring its potential as a therapeutic target. Capsaicin displayed promising drug-target interactions in molecular docking analyses. Additionally, metabolome- and proteome-wide MR (PWMR) analyses revealed 33 unique metabolites and critical inflammatory proteins such as FGF5 that are significantly linked to and colocalized with CKD and kidney function. These insights deepen our understanding of CKD pathogenesis and highlight novel targets for treatment and prevention.

Management Considerations for Acute Coronary Syndromes in Chronic Kidney Disease

PURPOSE OF REVIEW

Propensity of patients with chronic kidney disease (CKD) to adverse outcomes of acute coronary syndromes (ACS) derives, in part, from imperfection in management. Dearth of data resulting from underrepresentation of patients with CKD in ACS trials and underuse of evidence-based testing and therapy compound biological risks inherent to CKD. We sought in this narrative review to critically appraise contemporary evidence and offer suggested approaches to practicing clinicians for the optimization of ACS management in patients with CKD.

RECENT FINDINGS

Updated multisociety chest pain guidelines emphasize the diversity of clinical presentations of ACS, pertinent to recognition of ACS in patients with CKD. Evolving tools to predict and prevent acute kidney injury complicating invasive management of ACS serve to support improved access to and safety of percutaneous coronary intervention (PCI) in CKD patients, who remain at elevated risk. Growth in use of radial access, advances in PCI quality, incorporation of intravascular imaging, and new options and insights in pharmacotherapy contribute to an evolving calculus of ischemic and bleeding risk in ACS with bearing on management in CKD patients. Key opportunities to improve outcomes of ACS for patients with CKD center on avoiding underuse of beneficial medical and invasive therapies; enhancing safety of therapies by leveraging evidence-based strategies to prevent acute kidney injury; and devoting specific effort to investigation of ACS management in the context of CKD.

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

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

Increased cardiovascular risk in patients with chronic kidney disease

Cardiovascular disease (CVD) is highly prevalent in patients suffering from chronic kidney disease (CKD). The risk of patients with CKD developing CVD is manifested already in the early stages of CKD development. The impact of declined kidney function on increased cardiovascular risk and the underlying mechanisms are complex and multifactorial. This review discusses the impact of (a) traditional cardiovascular risk factors such as smoking, dyslipidemia, diabetes, and hypertension as well as (b) CKD-specific pathophysiological and molecular mechanisms associated with an increased cardiovascular risk. The latter include uremic toxins, post-translational modifications and uremic lipids, innate immune cell activation and inflammation, oxidative stress, endothelial cell dysfunction, increased coagulation and altered platelet responses, vascular calcification, renin-angiotensin-aldosterone-system (RAAS) and sympathetic activation, as well as anemia. Unraveling the complex interplay of different risk factors, especially in the context of patient subcohorts, will help to find new therapeutic approaches in order to reduce the increased cardiovascular risk in this vulnerable patient cohort.

Phosphate in Cardiovascular Disease: From New Insights Into Molecular Mechanisms to Clinical Implications

Hyperphosphatemia is a common feature in patients with impaired kidney function and is associated with increased risk of cardiovascular disease. This phenomenon extends to the general population, whereby elevations of serum phosphate within the normal range increase risk; however, the mechanism by which this occurs is multifaceted, and many aspects are poorly understood. Less than 1% of total body phosphate is found in the circulation and extracellular space, and its regulation involves multiple organ cross talk and hormones to coordinate absorption from the small intestine and excretion by the kidneys. For phosphate to be regulated, it must be sensed. While mostly enigmatic, various phosphate sensors have been elucidated in recent years. Phosphate in the circulation can be buffered, either through regulated exchange between extracellular and cellular spaces or through chelation by circulating proteins (ie, fetuin-A) to form calciprotein particles, which in themselves serve a function for bulk mineral transport and signaling. Either through direct signaling or through mediators like hormones, calciprotein particles, or calcifying extracellular vesicles, phosphate can induce various cardiovascular disease pathologies: most notably, ectopic cardiovascular calcification but also left ventricular hypertrophy, as well as bone and kidney diseases, which then propagate phosphate dysregulation further. Therapies targeting phosphate have mostly focused on intestinal binding, of which appreciation and understanding of paracellular transport has greatly advanced the field. However, pharmacotherapies that target cardiovascular consequences of phosphate directly, such as vascular calcification, are still an area of great unmet medical need.

Intracellular proteomics and extracellular vesiculomics as a metric of disease recapitulation in 3D-bioprinted aortic valve arrays

In calcific aortic valve disease (CAVD), mechanosensitive valvular cells respond to fibrosis- and calcification-induced tissue stiffening, further driving pathophysiology. No pharmacotherapeutics are available to treat CAVD because of the paucity of (i) appropriate experimental models that recapitulate this complex environment and (ii) benchmarking novel engineered aortic valve (AV)-model performance. We established a biomaterial-based CAVD model mimicking the biomechanics of the human AV disease-prone fibrosa layer, three-dimensional (3D)-bioprinted into 96-well arrays. Liquid chromatography-tandem mass spectrometry analyses probed the cellular proteome and vesiculome to compare the 3D-bioprinted model versus traditional 2D monoculture, against human CAVD tissue. The 3D-bioprinted model highly recapitulated the CAVD cellular proteome (94% versus 70% of 2D proteins). Integration of cellular and vesicular datasets identified known and unknown proteins ubiquitous to AV calcification. This study explores how 2D versus 3D-bioengineered systems recapitulate unique aspects of human disease, positions multiomics as a technique for the evaluation of high throughput-based bioengineered model systems, and potentiates future drug discovery.

Cardiovascular Consequences of Uremic Metabolites: an Overview of the Involved Signaling Pathways

The crosstalk of the heart with distant organs such as the lung, liver, gut, and kidney has been intensively approached lately. The kidney is involved in (1) the production of systemic relevant products, such as renin, as part of the most essential vasoregulatory system of the human body, and (2) in the clearance of metabolites with systemic and organ effects. Metabolic residue accumulation during kidney dysfunction is known to determine cardiovascular pathologies such as endothelial activation/dysfunction, atherosclerosis, cardiomyocyte apoptosis, cardiac fibrosis, and vascular and valvular calcification, leading to hypertension, arrhythmias, myocardial infarction, and cardiomyopathies. However, this review offers an overview of the uremic metabolites and details their signaling pathways involved in cardiorenal syndrome and the development of heart failure. A holistic view of the metabolites, but more importantly, an exhaustive crosstalk of their known signaling pathways, is important for depicting new therapeutic strategies in the cardiovascular field.

Food to Prevent Vascular Calcification in Chronic Kidney Disease

Vascular calcification (VC) is a consequence of chronic kidney disease (CKD) which is of paramount importance regarding the survival of CKD patients. VC is far from being controlled with actual medication; as a result, in recent years, diet modulation has become more compelling. The concept of medical nutritional therapy points out the idea that food may prevent or treat diseases. The aim of this review was to evaluate the influence of food habits and nutritional intervention in the occurrence and progression of VC in CKD. Evidence reports the harmfulness of ultra-processed food, food additives, and animal-based proteins due to the increased intake of high absorbable phosphorus, the scarcity of fibers, and the increased production of uremic toxins. Available data are more supportive of a plant-dominant diet, especially for the impact on gut microbiota composition, which varies significantly depending on VC presence. Magnesium has been shown to prevent VC but only in experimental and small clinical studies. Vitamin K has drawn considerable attention due to its activation of VC inhibitors. There are positive studies; unfortunately, recent trials failed to prove its efficacy in preventing VC. Future research is needed and should aim to transform food into a medical intervention to eliminate VC danger in CKD.

Variability in structure, morphology, and mechanical properties of the descending thoracic and infrarenal aorta around their circumference

Aortic diseases, such as aneurysms, atherosclerosis, and dissections, demonstrate a preferential development and progression around the aortic circumference, resulting in a highly heterogeneous disease state around the circumference. Differences in the aorta's structural composition and mechanical properties may be partly responsible for this phenomenon. Our goal in this study was to analyze the mechanical and structural properties of the human aorta at its lateral, anterior, posterior, and medial quadrants in two regions prone to circumferentially inhomogeneous diseases, descending Thoracic Aorta (TA) and Infrarenal Aorta (IFR). Human aortas were obtained from 10 donors (64 ± 11 years) and dissected from their loose surrounding tissue. Mechanical properties were determined in all four quadrants of TA and IFR using planar biaxial testing and fitted to three common constitutive models. The structure of tissues was assessed using Movat Pentachrome stained histology slides. We observed that the anterior quadrant exhibited the greatest thickness, followed by the lateral region, in both the TA and IFR. In TA, the posterior wall appeared as the stiffest location in most samples, while in IFR, the anterior wall was the stiffest. We observed a higher glycosaminoglycans content in the lateral and posterior regions of the IFR. We found elastin density to be similar in TA lateral, anterior, and posterior quadrants, while in IFR, the anterior region demonstrated the highest elastin density. Despite significant variations between subjects, this study highlights the distinct morphometrical, mechanical, and structural properties between the quadrants of both TA and IFR.

Secondary Hyperparathyroidism

Secondary hyperparathyroidism (SHPT) does not initiate as a primary dysfunction of parathyroid glands resulting from an intrinsic defect or disease but is the physiologic response of parathyroids to metabolic changes elsewhere in the body occurring over time. SHPT is a manifestation of a chronic condition that classically occurs from chronic kidney disease. In fact, given the relatively recent transition of populations from outside (agrarian) to indoor (industrial, information technology, and so forth) employment and a consequent reduction in sun exposure, combined with diets of highly processed food, vitamin D and calcium deficiencies are now the leading causes of SHPT.

Spice Up Your Kidney: A Review on the Effects of Capsaicin in Renal Physiology and Disease

Capsaicin, the organic compound which attributes the spicy flavor and taste of red peppers and chili peppers, has been extensively studied for centuries as a potential natural remedy for the treatment of several illnesses. Indeed, this compound exerts well-known systemic pleiotropic effects and may thus bring important benefits against various pathological conditions like neuropathic pain, rhinitis, itching, or chronic inflammation. Yet, little is known about the possible biological activity of capsaicin at the kidney level, as this aspect has only been addressed by sparse experimental investigations. In this paper, we aimed to review the available evidence focusing specifically on the effects of capsaicin on renal physiology, as well as its potential benefits for the treatment of various kidney disorders. Capsaicin may indeed modulate various aspects of renal function and renal nervous activity. On the other hand, the observed experimental benefits in preventing acute kidney injury, slowing down the progression of diabetic and chronic kidney disease, ameliorating hypertension, and even delaying renal cancer growth may set the stage for future human trials of capsaicin administration as an adjuvant or preventive therapy for different, difficult-to-treat renal diseases.

Medical Management of Coronary Artery Disease in Patients with Chronic Kidney Disease

Chronic kidney disease patients are at increased risk of cardiovascular disease, which is the leading cause of mortality among this population. In addition, chronic kidney disease is a major risk factor for the development of coronary artery disease and is widely regarded as a coronary artery disease risk equivalent. Medical therapy is the cornerstone of coronary artery disease management in the general population. However, there are few trials to guide medical therapy of coronary artery disease in chronic kidney disease, with most data extrapolated from clinical trials of mainly non-chronic kidney disease patients, which were not adequately powered to evaluate this subgroup. There is some evidence to suggest that the efficacy of certain therapies such as aspirin and statins is attenuated with declining estimated glomerular filtration rate, with questionable benefit among end-stage renal disease (ESRD) patients. Furthermore, chronic kidney disease and ESRD patients are at higher risk of potential side effects with therapy, which may limit their use. In this review, we summarize the available evidence supporting the safety and efficacy of medical therapy of coronary artery disease in chronic kidney disease and ESRD patients. We also discuss the data on new emerging therapies, including PCSK9i, SGLT2i, GLP1 receptor agonists, and nonsteroidal mineralocorticoid receptor antagonists, which show promise at reducing risk of cardiovascular events in the chronic kidney disease population and may offer additional treatment options. Overall, dedicated studies directly evaluating chronic kidney disease patients, particularly those with advanced chronic kidney disease and ESRD, are greatly needed to establish the optimal medical therapy for coronary artery disease and improve outcomes in this vulnerable population.

Association of dietary live microbe intake with abdominal aortic calcification in US adults: a cross-sectional study of NHANES 2013-2014

OBJECT

To explore the potential association between dietary live microbe intake and abdominal aortic calcification (AAC).

METHODS

We conducted a cross-section study based on the National Health and Nutrition Examination Survey (NHANES). We categorized the participants into three groups (low, medium, and high dietary intake of live microbes) according to Sanders's dietary live microbe classification system and participants' 24-h dietary recall data. AAC was quantified by using dual-energy X-ray absorptiometry (DXA) and diagnosed by using the Kauppila AAC-24 score system. The analyses utilized weighted logistic regression and weighted linear regression.

RESULTS

A total of 2,586 participants were included. After the full adjustment for covariates, compared to participants with a low dietary live microbe intake, participants with a high dietary live microbe intake had a significantly lower risk of severe AAC (OR: 0.39, 95% CI: 0.22, 0.68, p = 0.003), and the AAC score was also significantly decreased (β:-0.53, 95% CI: -0.83, -0.23, p = 0.002).

CONCLUSION

In this study, more dietary live microbial intake was associated with lower AAC scores and a lower risk of severe AAC. However, more research is needed to verify this.

Influence of sodium thiosulfate on coronary artery calcification of patients on dialysis: a meta-analysis

Coronary artery calcification (CAC) is common in dialysis patients and is associated with a higher risk of future cardiovascular events. Sodium thiosulfate (STS) is effective for calciphylaxis in dialysis patients; however, the influence of STS on CAC in dialysis patients remains unclear. This systematic review and meta-analysis were conducted to evaluate the effects of STS on CAC in patients undergoing dialysis. PubMed, Embase, Cochrane Library, CNKI, and Wanfang databases were searched from inception to 22 March 2023 for controlled studies comparing the influence of STS versus usual care without STS on CAC scores in dialysis patients. A random effects model incorporating the potential influence of heterogeneity was used to pool the results. Nine studies, including two non-randomized studies and seven randomized controlled trials, were included in the meta-analysis. Among these, 365 patients on dialysis were included in the study. Compared with usual care without STS, intravenous STS for 3-6 months was associated with significantly reduced CAC scores (mean difference [MD] = -180.17, 95% confidence interval [CI]: -276.64 to -83.70, p < 0.001, I2 = 0%). Sensitivity analysis limited to studies of patients on hemodialysis showed similar results (MD: -167.33, 95% CI: -266.57 to -68.09, p = 0.001; I2 = 0%). Subgroup analyses according to study design, sample size, mean age, sex, dialysis vintage of the patients, and treatment duration of STS also showed consistent results (p for subgroup differences all > 0.05). In conclusion, intravenous STS may be effective in attenuating CAC in dialysis patients.

Future treatment of vascular calcification in chronic kidney disease

INTRODUCTION

Cardiovascular disease (CVD) is one of the global leading causes of morbidity and mortality in chronic kidney disease (CKD) patients. Vascular calcification (VC) is a major cause of CVD in this population and is the consequence of complex interactions between inhibitor and promoter factors leading to pathological deposition of calcium and phosphate in soft tissues. Different pathological landscapes are associated with the development of VC, such as endothelial dysfunction, oxidative stress, chronic inflammation, loss of mineralization inhibitors, release of calcifying extracellular vesicles (cEVs) and circulating calcifying cells.

AREAS COVERED

In this review, we examined the literature and summarized the pathophysiology, biomarkers and focused on the treatments of VC.

EXPERT OPINION

Even though there is no consensus regarding specific treatment options, we provide the currently available treatment strategies that focus on phosphate balance, correction of vitamin D and vitamin K deficiencies, avoidance of both extremes of bone turnover, normalizing calcium levels and reduction of inflammatory response and the potential and promising therapeutic approaches liketargeting cellular mechanisms of calcification (e.g. SNF472, TNAP inhibitors).Creating novel scores to detect in advance VC and implementing targeted therapies is crucial to treat them and improve the future management of these patients.