Inflammatory cytokines and reactive oxygen species as mediators of chronic kidney disease-related vascular calcification

Key regulators of vascular calcification in chronic kidney disease: Hyperphosphatemia, BMP2, and RUNX2

Vascular calcification is quite common in patients with end-stage chronic kidney disease and is a major trigger for cardiovascular complications in these patients. These complications significantly impact the survival rate and long-term prognosis of individuals with chronic kidney disease. Numerous studies have demonstrated that the development of vascular calcification involves various pathophysiological mechanisms, with the osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs) being of utmost importance. High phosphate levels, bone morphogenetic protein 2 (BMP2), and runt-related transcription factor 2 (RUNX2) play crucial roles in the osteogenic transdifferentiation process of VSMCs. This article primarily reviews the molecular mechanisms by which high phosphate, BMP2, and RUNX2 regulate vascular calcification secondary to chronic kidney disease, and discusses the complex interactions among these factors and their impact on the progression of vascular calcification. The insights provided here aim to offer new perspectives for future research on the phenotypic switching and osteogenic transdifferentiation of VSMCs, as well as to aid in optimizing clinical treatment strategies for this condition, bearing significant clinical and scientific implications.

The mechanisms underlying acute myocardial infarction in chronic kidney disease patients undergoing hemodialysis

Cardiovascular disease (CVD) is a leading cause of death in chronic kidney disease (CKD). Hemodialysis is one of the main treatments for patients with end-stage kidney disease. Epidemiological data has shown that acute myocardial infarction (AMI) accounts for the main reason for death in patients with CKD under hemodialysis therapy. Immune dysfunction and changes in metabolism (including a high level of inflammatory cytokines, a disorder of lipid and mineral ion homeostasis, accumulation of uremic toxins et al.) during CKD can deteriorate stability of atherosclerotic plaque and promote vascular calcification, which are exactly the pathophysiological mechanisms underlying the occurrence of AMI. Meanwhile, the hemodialysis itself also has adverse effects on lipoprotein, the immune system and hemodynamics, which contribute to the high incidence of AMI in these patients. This review aims to summarize the mechanisms and further promising methods of prevention and treatment of AMI in CKD patients undergoing hemodialysis, which can provide an excellent paradigm for exploring the crosstalk between the kidney and cardiovascular system.

Association of Estimated Glomerular Filtration Rate Trajectories with Atrial Fibrillation Risk in Populations with Normal or Mildly Impaired Renal Function

Introduction

The association between the longitudinal patterns of estimated glomerular filtration rate (eGFR) and risk of atrial fibrillation (AF) in populations with normal or mildly impaired renal function is not well characterized. We sought to explore the eGFR trajectories in populations with normal or mildly impaired renal function and their association with AF.

Methods

This prospective cohort study included 62,407 participants who were free of AF, cardiovascular diseases, and moderate to severe renal insufficiency (eGFR <60 mL/min/1.73 m2) before 2010. The eGFR trajectories were developed using latent mixture modeling based on examination data in 2006, 2008, and 2010. Incident AF cases were identified in biennial electrocardiogram assessment and a review of medical insurance data and discharge registers. We used Cox regression models to estimate the hazard ratios and 95% confidence intervals (CIs) for incident AF.

Results

According to survey results for the range and changing pattern of eGFR during 2006-2010, four trajectories were identified: high-stable (range, 107.47-110.25 mL/min/1.73 m2; n = 11,719), moderate-increasing (median increase from 83.83 to 100.37 mL/min/1.73 m2; n = 22,634), high-decreasing (median decrease from 101.72 to 89.10 mL/min/1.73 m2; n = 7,943), and low-stable (range, 73.48-76.78 mL/min/1.73 m2; n = 20,111). After an average follow-up of 9.63 years, a total of 485 cases of AF were identified. Compared with the high-stable trajectory, the adjusted hazard ratios of AF were 1.70 (95% CI, 1.09-2.66) for the moderate-increasing trajectory, 1.92 (95% CI, 1.18-3.13) for the high-decreasing trajectory, and 2.28 (95% CI, 1.46-3.56) for the low-stable trajectory. The results remained consistent across a number of sensitivity analyses.

Conclusion

The trajectories of eGFR were associated with subsequent AF risk in populations with normal or mildly impaired renal function.

Costunolide Inhibits Chronic Kidney Disease Development by Attenuating IKKβ/NF-κB Pathway

Background

Chronic kidney disease (CKD) is a significant worldwide health concern that leads to high mortality rates. The bioactive substance costunolide (CTD) has demonstrated several pharmacological effects and holds promise as a CKD treatment. This study aims to investigate the impact of CTD on CKD and delve into its mechanisms of action.

Methods

Unilateral ureteral obstruction (UUO) methods and renal fibrosis mice models were created. Various concentrations of CTD were injected into UUO mice models to investigate the therapeutic effects of CTD on renal fibrosis of mice. Then, renal morphology, pathological changes, and the expression of genes related to fibrosis, inflammation and ferroptosis were analysed. RNA sequencing was utilized to identify the main biological processes and pathways involved in renal injury. Finally, both overexpression and inhibition of IKKβ were studied to examine their respective effects on fibrosis and inflammation in both in vitro and in vivo models.

Results

CTD treatment was found to significantly alleviate fibrosis, inflammation and ferroptosis in UUO-induced renal fibrosis mice models. The results of RNA sequencing suggested that the IKKβ acted as key regulatory factor in renal injury and the expression of IKKβ was increased in vitro and in vivo renal fibrosis model. Functionally, down-regulated IKKβ expression inhibits ferroptosis, inflammatory cytokine production and collagen deposition. Conversely, IKKβ overexpression exacerbates progressive renal fibrosis. Mechanistically, CTD alleviated renal fibrosis and inflammation by inhibiting the expression of IKKβ and attenuating IKKβ/NF-κB pathway.

Conclusion

This study demonstrates that CTD could mitigate renal fibrosis, ferroptosis and inflammation in CKD by modulating the IKKβ/NF-κB pathway, which indicates targeting IKKβ has an enormous potential for treating CKD.

Low-dose aspirin for prevention of cardiovascular mortality in patients with type 2 diabetes and chronic kidney disease: A real-world nationwide cohort study

AIMS/INTRODUCTION

Cardiovascular mortality risk is elevated among patients with diabetes and concurrent chronic kidney disease. However, controversy surrounds the use of aspirin for primary prevention within this population. This study aims to assess the effectiveness and safety of low-dose aspirin for primary prevention in patients with diabetes and pre-end-stage renal disease.

MATERIALS AND METHODS

This was a retrospective population-based cohort study using the National Health Insurance Research Database in Taiwan. The study included adults with type 2 diabetes who were enrolled in the pre-end-stage renal disease pay-for-performance program and had no atherosclerotic cardiovascular disease. We used propensity score analysis to control baseline characteristics between the two groups. Clinical outcomes including cardiovascular mortality, all-cause mortality, major bleeding, and renal disease progression were compared between patients who first received aspirin and those who did not.

RESULTS

Between January 2012 and December 2015, a total of 2,155 low-dose aspirin users and 6,737 nonaspirin users were identified. Following propensity score adjustment, aspirin use exhibited a comparable risk of cardiovascular death compared with nonaspirin users (adjusted hazard ratio [aHR] 1.12; 95% confidence interval [CI] 0.65-1.95; P = 0.681). The risk of all-cause mortality was similar between the two groups (aHR 1.07; 95% CI 0.92-1.24; P = 0.385). Similar risks were observed in terms of major bleeding and renal disease progression.

CONCLUSIONS

In patients with diabetes and pre-end-stage renal disease who lacked atherosclerotic cardiovascular disease, low-dose aspirin did not demonstrate a reduction in mortality. These findings do not support the use of aspirin for primary prevention in this high-risk population.

The mechanism underlying correlation of particulate matter-induced ferroptosis with inflammasome activation and iron accumulation in macrophages

Particulate matter (PM) is a global environmental hazard, which affects human health through free radical production, cell death induction, and immune responses. PM activates inflammasomes leading to excessive inflammatory responses and induces ferroptosis, a type of cell death. Despite ongoing research on the correlation among PM-induced ferroptosis, immune response, and inflammasomes, the underlying mechanism of this relationship has not been elucidated. In this study, we demonstrated the levels of PM-induced cell death and immune responses in murine macrophages, J774A.1 and RAW264.7, depending on the size and composition of particulate matter. PM2.5, with extraction ions, induced significant levels of cell death and immune responses; it induces lipid peroxidation, iron accumulation, and reactive oxygen species (ROS) production, which characterize ferroptosis. In addition, inflammasome-mediated cell death occurred owing to the excessive activation of inflammatory responses. PM-induced iron accumulation activates ferroptosis and inflammasome formation through ROS production; similar results were observed in vivo. These results suggest that the link between ferroptosis and inflammasome formation induced by PM, especially PM2.5 with extraction ions, is established through the iron-ROS axis. Moreover, this study can effectively facilitate the development of a new therapeutic strategy for PM-induced immune and respiratory diseases.

Calcitriol combined with high-calcium and high-phosphorus diet induces vascular calcification model in chronic kidney disease rats

BACKGROUND

Cardiovascular diseases represent a significant complication arising from chronic kidney disease (CKD). Vascular calcification is an important risk factor for cardiovascular diseases. Reducing vascular calcification is therefore critical to reducing mortality in CKD patients.

HYPOTHESIS

This study aims to establish a vascular calcification model in rats with CKD by administering subcutaneous injections of calcitriol in combination with a high-calcium and high-phosphorus diet.

METHODS

The rats were divided into the CKD vascular calcification model group (subtotal nephrectomy+ [SNx+]) and the sham-operated control group (subtotal nephrectomy- [SNx-]). The rats in the SNx(+) group were administered high-calcium and high-phosphorus feeds following a 5/6 nephrectomy. Calcitriol (1 μg/kg, three times a week) was injected subcutaneously at weeks 0, 4, 8, and 12 after the operation. Measurements of body weight, urine, serum biochemical indicators and vascular calcification level were conducted in rats.

RESULTS

(1) Compared with the SNx(-) group, rats in the SNx(+) group experienced an increase in 24-h urine output, urinary phosphorus, and urinary microprotein excretion, along with the development of severe anemia. Additionally, there was a notable elevation in serum phosphorus, blood urea nitrogen, blood creatinine, fibroblast growth factor 23 (FGF-23), and intact parathyroid hormone levels, accompanied by severe hypoproteinemia at week 12. (2) The results of micro-compuyed tomography (μCT) and alizarin S staining of the thoracic aorta demonstrated an increase in vascular calcification in the SNx(+) group. (3) The expression levels of vascular calcification-related proteins were increased.

CONCLUSIONS

The administration of calcitriol combined with a high-calcium and high-phosphorus diet was found to induce vascular calcification in CKD rats, leading to a disturbance in mineral metabolism. Vascular calcification was effectively induced in CKD rats after 12 weeks of modeling, thereby presenting a novel approach for establishing a vascular calcification model in CKD rats, helping to elucidate this clinical condition and its underlying molecular mechanisms.

The Bone-Vascular Axis in Chronic Kidney Disease: From Pathophysiology to Treatment

PURPOSE OF REVIEW

This review aims to describe the pathogenic factors involved in bone-vessel anomalies in CKD which are the object of numerous experimental and clinical research.

RECENT FINDINGS

Knowledge on the pathophysiological mechanisms involved in the regulation of vascular calcification and mineral-bone disorders is evolving. Specific bone turnover anomalies influence the vascular health while recent studies demonstrate that factors released by the calcified vessels also contribute to bone deterioration in CKD. Current therapies used to control mineral dysregulations will impact both the vessels and bone metabolism. Available anti-osteoporotic treatments used in non-CKD population may negatively or positively affect vascular health in the context of CKD. It is essential to study the bone effects of the new therapeutic options that are currently under investigation to reduce vascular calcification. Our paper highlights the complexity of the bone-vascular axis and discusses how current therapies may affect both organs in CKD.

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

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

Associations of Whole Blood Zinc Levels with Coronary Artery Calcification and Future Cardiovascular Events in CKD Patients

This study was conducted to compare the differences of the whole blood zinc concentration in patients with chronic kidney disease (CKD) as compared to healthy controls, and to explore the correlations of the whole blood zinc level with coronary artery calcification (CAC) and cardiovascular event (CVE) in CKD patients. A total of 170 CKD patients and 62 healthy controls were recruited. The whole blood zinc concentration was determined in using atomic absorption spectroscopy (AAS) method. The degrees of CAC were evaluated by Agatston score based on computed tomography (CT). Regular follow-up visits were performed to record the incidence of CVE, and risk factors were analyzed by COX proportional hazard model and Kaplan-Meier survival curve. There were statistically significant lower zinc levels in CKD patients than in healthy population. The prevalence of CAC was 58.82% in CKD patients. Correlation analysis showed that dialysis duration, intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), 25-hydroxyvitamin D3 (25(OH)D3), neutrophil-lymphocyte ratio (NLR), total cholesterol (TC), and high-sensitive C-reactive protein (Hs-CRP) were positively correlated with CAC, while albumin (ALB), hemoglobin (Hb), and zinc levels were negatively associated with CAC. Further COX proportional hazard model demonstrated that moderate to severe CAC, NLR, phosphate, 25(OH)D3, iPTH, and high-density lipoprotein (HDL) were associated with an increased risk for CVE, while zinc levels, Hb, and ALB were inversely associated with a reduced risk for CVE. Kaplan-Meier curve showed that low zinc (zinc < 86.62 μmol/L) patients and moderate to severe CAC patients had lower survival respectively. Our study found the lower levels of zinc and higher prevalence of CAC in CKD patients; the low zinc is involved in the high incidence rate of moderate to severe CAC and CVE in CKD patients.

Vascular calcification and cellular signaling pathways as potential therapeutic targets

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

Relationship between gut microbiota and vascular calcification in hemodialysis patients

INTRODUCTION

Vascular calcification (VC) is an independent risk factor for cardiovascular mortality in end-stage renal disease (ESRD) patients. The pathogenesis of VC is complicated and unclear. Uremic toxins produced by gut microbiota can promote VC. This study aims to identify the differences in gut microbiota between the different VC groups and the main bacteria associated with VC in hemodialysis (HD) patients in an attempt to open up new preventive and therapeutic approaches and define the probable mechanism for VC in HD patients in the future.

METHODS

A total of 73 maintenance HD patients were enrolled in this cross-sectional study. According to the abdominal aortic calcification (AAC) scores, the participants were divided into the high AAC score group and the low AAC score group. High-throughput sequencing of the gut microbiota was performed and the results were evaluated by alpha diversity, beta diversity, species correlation, and model predictive analyses.

RESULTS

The prevalence of VC was 54.79% (40/73) in the study. The majority of phyla in the two groups were the same, including Firmicutes, Actinobacteriota, Proteobacteria, and Bacteroidota. The microbial diversity in the high AAC score group had a decreasing trend (p = 0.050), and the species abundance was significantly lower (p = 0.044) than that in the low AAC score group. The HD patients with high AAC scores showed an increased abundance of Proteobacteria and decreased abundances of Bacteroidota and Synergistota at the phylum level; increased abundances of Escherichia-Shigella, Ruminococcus_gnavus_group, and Lactobacillus; and decreased abundances of Ruminococcus and Lachnospiraceae_NK4A136_group at the genus level (p<0.05). Escherichia-Shigella and Ruminococcus_gnavus_group were positively correlated with VC, and Ruminococcus, Adlercreutzia, Alistipes, and norank_f__Ruminococcaceae were negatively correlated with VC. Escherichia-Shigella had the greatest influence on VC in HD patients, followed by Ruminococcus and Butyricimonas.

CONCLUSIONS

Our results provide clinical evidence that there was a difference in gut microbiota between the different VC groups in HD patients. Escherichia-Shigella, a lipopolysaccharide (LPS)-producing bacterium, was positively correlated with VC and had the greatest influence on VC. Ruminococcus, a short-chain fatty acid (SCFA)-producing bacterium, was negatively correlated with VC and had the second strongest influence on VC in HD patients. The underlying mechanism is worth studying. These findings hint at a new therapeutic target.

The pterostilbene-dihydropyrazole derivative Ptd-1 ameliorates vascular calcification by regulating inflammation

Vascular calcification is an independent risk factor for cardiovascular disease. However, there is still a lack of adequate treatment. This study aimed to examine the potential of (E)-1-(5-(2-(4-fluorobenzyloxy)Styryl)-4,6-dimethoxyphenyl)-3-methyl-4,5-dihydro-1H-pyrazole-1-yl) ethyl ketone (Ptd-1) to alleviate vascular calcification. ApoE-deficient mice were fed a high-fat diet for 12/16 weeks to induce intimal calcification, and wild-type mice were induced with a combination of nicotine and vitamin D3 to induce medial calcification. Human aortic smooth muscle cells (HASMCs) and aortic osteogenic differentiation were induced in vitro with phosphate. In the mouse model of atherosclerosis, Ptd-1 significantly ameliorated the progression of atherosclerosis and intimal calcification, and there were significant reductions in lipid deposition and calcium salt deposition in the aorta and aortic root. In addition, Ptd-1 significantly improved medial calcification in vivo and osteogenic differentiation in vitro. Mechanistically, Ptd-1 reduced the levels of the inflammatory factors IL-1β, TNFα and IL-6 in vivo and in vitro. Furthermore, we demonstrated that Ptd-1 could attenuate the expression of p-ERK1/2 and β-catenin, and that the levels of inflammatory factors were elevated in the presence of ERK1/2 and β-catenin agonists. Interestingly, we determined that activation of the ERK1/2 pathway promoted β-catenin expression, which further regulated the IL-6/STAT3 signaling pathway. Ptd-1 blocked ERK1/2 signaling, leading to decreased expression of inflammatory factors, which in turn improved vascular calcification. Taken together, our study reveals that Ptd-1 ameliorates vascular calcification by regulating the production of inflammatory factors, providing new ideas for the treatment of vascular calcification.

Antihypertensive treatment with hydrochlorothiazide-hydralazine combination aggravates medial vascular calcification in CKD rats with mineral bone disorder

Background

Arterial stiffness and medial vascular calcification, leading to isolated systolic blood pressure (BP), are major cardiovascular risk factors in patients with chronic kidney disease (CKD) and mineral bone disorders (MBD). The impact of BP on MBD-induced medial vascular calcification in CKD remains uncertain. We investigated whether BP reduction improves arterial stiffness and medial vascular calcification in a rat model of CKD-MBD.

Methods

CKD was induced in Wistar rats by subtotal nephrectomy. Then, MBD was generated by a Ca/P-rich diet with calcitriol supplementation to induce medial vascular calcification. Two antihypertensive treatments were evaluated: (1) the angiotensin AT1 receptor antagonist losartan, and (2) the combination of the thiazide diuretic hydrochlorothiazide and the direct vasodilator hydralazine (HCTZ/HY). After 5 weeks, mean BP (MBP), pulse pressure (PP), and pulse wave velocity (PWV) were determined. Vascular calcification was assessed in the thoracic aorta.

Results

While MBP was similar in CKD-MBD and control CKD rats, PP and PWV were increased in CKD-MBD rats. The heightened arterial stiffness in CKD-MBD rats was associated with diffused medial calcification along the thoracic aorta. Although both losartan and HCTZ/HY reduced MBP in CKD-MBD rats, losartan did not affect PP and PWV nor medial vascular calcification, whereas HCTZ/HY, unexpectedly, further increased arterial stiffness and medial vascular calcification.

Conclusion

In the rat model of CKD-MBD, antihypertensive treatment with losartan did not affect arterial stiffness or medial vascular calcification. However, HCTZ/HY treatment aggravated arterial stiffness and vascular calcification despite a similar reduction of MBP, suggesting a blood pressure-independent mechanism for vascular calcification.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Empagliflozin Attenuates Vascular Calcification in Mice with Chronic Kidney Disease by Regulating the NFR2/HO-1 Anti-Inflammatory Pathway through AMPK Activation

Vascular calcification (VC) is associated with increased cardiovascular risks in patients with chronic kidney disease (CKD). Sodium-glucose cotransporter 2 inhibitors, such as empagliflozin, can improve cardiovascular and renal outcomes. We assessed the expression of Runt-related transcription factor 2 (Runx2), interleukin (IL)-1β, IL-6, AMP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor (Nrf2), and heme oxygenase 1 (HO-1) in inorganic phosphate-induced VC in mouse vascular smooth muscle cells (VSMCs) to investigate the mechanisms underlying empagliflozin's therapeutic effects. We evaluated biochemical parameters, mean artery pressure (MAP), pulse wave velocity (PWV), transcutaneous glomerular filtration rate (GFR), and histology in an in vivo mouse model with VC induced by an oral high-phosphorus diet following a 5/6 nephrectomy in ApoE^-/- mice. Compared to the control group, empagliflozin-treated mice showed significant reductions in blood glucose, MAP, PWV, and calcification, as well as increased calcium and GFR levels. Empagliflozin inhibited osteogenic trans-differentiation by decreasing inflammatory cytokine expression and increasing AMPK, Nrf2, and HO-1 levels. Empagliflozin mitigates high phosphate-induced calcification in mouse VSMCs through the Nrf2/HO-1 anti-inflammatory pathway by activating AMPK. Animal experiments suggested that empagliflozin reduces VC in CKD ApoE^-/- mice on a high-phosphate diet.

Asymptomatic hyperuricaemia in chronic kidney disease: mechanisms and clinical implications

Asymptomatic hyperuricaemia (HU) is considered a pathogenic factor in multiple disease contexts, but a causative role is only proven for the crystalline form of uric acid in gouty arthritis and urate nephropathy. Epidemiological studies document a robust association of HU with hypertension, cardiovascular disease (CVD) and CKD progression, but CKD-related impaired uric acid (UA) clearance and the use of diuretics that further impair UA clearance likely accounts for these associations. Interpreting the available trial evidence is further complicated by referring to xanthine oxidase inhibitors as urate-lowering treatment, although these drugs inhibit other substrates, so attributing their effects only to HU is problematic. In this review we provide new mechanistic insights into the biological effects of soluble and crystalline UA and discuss clinical evidence on the role of asymptomatic HU in CKD, CVD and sterile inflammation. We identify research areas with gaps in experimental and clinical evidence, specifically on infectious complications that represent the second common cause of death in CKD patients, referred to as secondary immunodeficiency related to kidney disease. In addition, we address potential therapeutic approaches on how and when to treat asymptomatic HU in patients with kidney disease and where further interventional studies are required.

ADAM10 and ADAM17, Major Regulators of Chronic Kidney Disease Induced Atherosclerosis?

Chronic kidney disease (CKD) is a major health problem, affecting millions of people worldwide, in particular hypertensive and diabetic patients. CKD patients suffer from significantly increased cardiovascular disease (CVD) morbidity and mortality, mainly due to accelerated atherosclerosis development. Indeed, CKD not only affects the kidneys, in which injury and maladaptive repair processes lead to local inflammation and fibrosis, but also causes systemic inflammation and altered mineral bone metabolism leading to vascular dysfunction, calcification, and thus, accelerated atherosclerosis. Although CKD and CVD individually have been extensively studied, relatively little research has studied the link between both diseases. This narrative review focuses on the role of a disintegrin and metalloproteases (ADAM) 10 and ADAM17 in CKD and CVD and will for the first time shed light on their role in CKD-induced CVD. By cleaving cell surface molecules, these enzymes regulate not only cellular sensitivity to their micro-environment (in case of receptor cleavage), but also release soluble ectodomains that can exert agonistic or antagonistic functions, both locally and systemically. Although the cell-specific roles of ADAM10 and ADAM17 in CVD, and to a lesser extent in CKD, have been explored, their impact on CKD-induced CVD is likely, yet remains to be elucidated.

Implications of Senescent Cell Burden and NRF2 Pathway in Uremic Calcification: A Translational Study

Increased senescent cell burden and dysregulation of the nuclear factor erythroid 2-related factor 2 (NRF2) pathway have been associated with numerous age-related pathologies; however, their role in promoting vascular calcification (VC) in chronic kidney disease (CKD) has yet to be determined. We investigated whether senescence and NRF2 pathways may serve as drivers of uremia-induced VC using three complementary approaches: a novel model of induced VC in 5/6-nephrectomized rats supplemented with high phosphate and vitamin D; epigastric arteries from CKD patients with established medial calcification; and vascular smooth muscle cells (VSMCs) incubated with uremic serum. Expression of p16^Ink4a and p21^Cip1, as well as γ-H2A-positive cells, confirmed increased senescent cell burden at the site of calcium deposits in aortic sections in rats, and was similarly observed in calcified epigastric arteries from CKD patients through increased p16^Ink4a expression. However, uremic serum-induced VSMC calcification was not accompanied by senescence. Expression of NRF2 and downstream genes, Nqo1 and Sod1, was associated with calcification in uremic rats, while no difference was observed between calcified and non-calcified EAs. Conversely, in vitro uremic serum-driven VC was associated with depleted NRF2 expression. Together, our data strengthen the importance of senescence and NRF2 pathways as potential therapeutic options to combat VC in CKD.

Combined cardiomegaly and aortic arch calcification predict mortality in hemodialysis patients

INTRODUCTION

This study aimed to investigate the relationship between cardiomegaly and aortic arch calcification (AAC) and overall/cardiovascular mortality in hemodialysis patients.

METHODS

We conducted a retrospective cohort study and enrolled patients who underwent initial hemodialysis. Cardiomegaly and AAC were determined by chest radiography and classified into four groups according to cross-classification of cardiothoracic ratio (CTR) of 0.5 and lower/higher grade AAC (LGAAC/HGAAC). The relationship between these groups and mortality was then analyzed by Cox proportional hazards model.

RESULTS

In multivariate Cox regression analysis, those in CTR ≤ 0.5 and HGAAC [hazard ratio (95% confidence interval): 2.07 (1.14-3.77)], CTR > 0.5 & LGAAC [3.60 (2.07-6.25)] and CTR > 0.5 & HGAAC [3.42 (2.03-5.77)] were significantly associated with overall mortality; while those in CTR > 0.5 & LGAAC [2.81 (1.28-6.19)] and CTR > 0.5 & HGAAC [2.32 (1.09-4.95)] were significantly related to cardiovascular mortality.

CONCLUSION

Combined cardiomegaly and AAC predicted overall and cardiovascular mortality in hemodialysis patients.

Dietary Mg Supplementation Decreases Oxidative Stress, Inflammation, and Vascular Dysfunction in an Experimental Model of Metabolic Syndrome with Renal Failure

BACKGROUND

Metabolic syndrome (MetS) and chronic kidney disease (CKD) are commonly associated with cardiovascular disease (CVD) and in these patients Mg concentration is usually decreased. This study evaluated whether a dietary Mg supplementation might attenuate vascular dysfunction through the modulation of oxidative stress and inflammation in concurrent MetS and CKD.

METHODS

A rat model of MetS (Zucker strain) with CKD (5/6 nephrectomy, Nx) was used. Nephrectomized animals were fed a normal 0.1%Mg (MetS+Nx+Mg0.1%) or a supplemented 0.6%Mg (MetS+Nx+Mg0.6%) diet; Sham-operated rats with MetS receiving 0.1%Mg were used as controls.

RESULTS

As compared to controls, the MetS+Nx-Mg0.1% group showed a significant increase in oxidative stress and inflammation biomarkers (lipid peroxidation and aortic interleukin-1b and -6 expression) and Endothelin-1 levels, a decrease in nitric oxide and a worsening in uremia and MetS associated pathology as hypertension, and abnormal glucose and lipid profile. Moreover, proteomic evaluation revealed changes mainly related to lipid metabolism and CVD markers. By contrast, in the MetS+Nx+Mg0.6% group, these parameters remained largely similar to controls.

CONCLUSION

In concurrent MetS and CKD, dietary Mg supplementation reduced inflammation and oxidative stress and improved vascular function.

Health-related patterns and chronic kidney disease in the Brazilian population: National Health Survey, 2019

Objective

The aim of this study was to identify patterns related to health and their association with chronic kidney disease (CKD) in the Brazilian population.

Methods

We used data from the National Health Survey (PNS), 2019. Participants were interviewed and answered questions related to socioeconomic and demographic information (gender, age, education, race/color), health conditions (presence of hypertension, diabetes mellitus, hyperlipidemia, cardiovascular disease, overweight and CKD) and lifestyle (smoking, alcohol consumption, physical activity and food consumption). To identify patterns, we used exploratory factor analysis. We performed logistic regression models to describe the association of CKD with each pattern in crude models and adjusted for gender, age group, education level and race/color.

Results

A total of 90,846 individuals were evaluated. The prevalence of CKD was 1.49% (95% CI: 1.3-1.6). Three health-related patterns - metabolic factors, behavioral risk factors and behavioral protective factors - were identified by factor analysis. Metabolic factors were determined by the presence of hypertension, diabetes mellitus, hyperlipidemia and cardiovascular diseases. Behavioral risk factors were determined by smoking, alcohol consumption, regular consumption of soft drinks, sweets and artificial juices, and high salt consumption. The protective behavioral factors were established by the practice of physical activity and regular consumption of vegetables and fruits. Participants of the highest tertile for metabolic factors were more likely to have CKD in the adjusted model (OR = 3.61, 95% CI: 2.69-4.85), when compared to those of the lower tertile.

Conclusion

The pattern referring to metabolic factors was associated with a higher chance of presenting CKD.

Polypharmacy, chronic kidney disease, and mortality among older adults: A prospective study of National Health and nutrition examination survey, 1999-2018

Introduction

Polypharmacy might contribute to a range of adverse outcomes, which could get worse in the elderly with chronic kidney disease (CKD). Evidence on polypharmacy, CKD, and mortality is scarce. We aimed to investigate the prospective association between polypharmacy, CKD and all-cause and cause-specific mortality in adults aged ≥65 years.

Methods

A total of 13,513 adults from the National Health and Nutrition Examination Surveys were included, following up from 1999 to 2018 until December 31, 2019. The simultaneous use of ≥5 medications by one individual was defined as polypharmacy. Survey-weighted Cox proportional hazard models were used to estimate the hazard ratio (HRs) for mortality from all-cause, cardiovascular diseases (CVD), and cancer after adjusting for potential confounding factors.

Results

Among the elderly with CKD, we identified 3,825 total deaths (1,325 CVD and 714 cancer) during a median follow-up of 7.7 years. Participants with polypharmacy had a 27% (HR = 1.27 [1.15, 1.39]) and 39% (HR = 1.39 [1.19, 1.62]) higher risk of all-cause and CVD mortality, respectively, but not for cancer mortality. Compared with the elderly with no polypharmacy and no CKD, the corresponding HRs (95%CIs) for all-cause mortality were 1.04 (0.96, 1.14) for those with no polypharmacy but CKD, 1.24 (1.11, 1.39) for with polypharmacy but no CKD, and 1.34 (1.21, 1.49) for those with both polypharmacy and CKD. A similar pattern was detected for CVD mortality.

Discussion

Polypharmacy was associated with elevated risks of all-cause and CVD mortality among the elderly CKD patients. More evidence-based approaches should be promoted for the appropriate deprescribing in the older adults with CKD.

The relationship between platelet distribution width and new-onset cardiovascular disease events in patients with peritoneal dialysis

Objectives

The global mortality rate from chronic kidney disease (CKD) has increased over the past two decades. Typically, peritoneal dialysis (PD) remains a useful alternative treatment for end-stage renal disease. Cardiovascular disease (CVD) is the main complication in PD patients. In terms of prognosis, it is reported that platelet distribution width (PDW) can predict adverse CVD events. However, the relationship between PDW and new-onset CVD in PD patients is not clear. This study aimed to explore the relationship between PDW and new-onset CVD in PD patients.

Methods

This was a retrospective cohort study, from 4 July 2005 to 31 December 2019, and a total of 1557 patients were recruited. PDW was respectively categorized into two groups: PDW ≤13.2 fL and PDW >13.2 fL. The primary outcome was a new-onset CVD event. Cox proportional hazards models were performed to assess the hazard ratio (HR). Receiver-operating characteristic (ROC) curves were applied to evaluate the predictive accuracy of the PDW on CVD events.

Results

During follow-up, 114 new-onset CVD events were recorded. Cox proportional hazards models showed a higher risk of CVD events in patients with high PDW (HR = 1.862 95%CI 1.205–2.877, p = 0.005). Kaplan–Meier cumulative incidence curves showed the risk of the first occurrence of CVD events was greater in the high PDW group (p = 0.006).

Conclusions

High PDW is associated with new-onset cardiovascular disease events in PD patients.

The effects for inflammatory responses by CPP with different colloidal properties in hemodialysis patients

Calciprotein particles (CPPs) are colloids composed of solid-phase calcium-phosphate and serum protein fetuin-A. CPPs form a polydispersed system with different particle size and density. CPPs with specific physical properties can induce calcification and innate immune responses in cultured cells. In hemodialysis patients, blood CPP levels were reported to correlate with vascular calcification and inflammation. However, little is known about relation between these disorders and physical properties of CPPs. Here, we show that the association between physical properties of plasma CPPs and serum levels of inflammatory cytokines/chemokines in 78 hemodialysis out-patients by cross-sectional study. Patients with cardiovascular disease (CVD) had significantly higher high density CPP (H-CPP) levels than patients without CVD but not low density CPP (L-CPP). Seven cytokines/chemokines (EGF, eotaxin, IL-8, IP-10, MCP-1, MIP-1, MIP-1β and TNFα) were detectable in the serum samples from > 95% of the patients. In multivariate regression analysis, H-CPP was positively associated with eotaxin after adjusting for age, gender, smoking, serum phosphate and FGF23. L-CPP was negatively associated with IL-8 after adjusting for age, gender, serum albumin, phosphate and FGF23. High H-CPP levels were associated with pro-inflammatory response, whereas L-CPPs were associated with anti-inflammatory response. CPPs with different physical properties may impact differently on pathophysiology in HD patients.

Overview on hydrogen sulfide-mediated suppression of vascular calcification and hemoglobin/heme-mediated vascular damage in atherosclerosis

Vulnerable atherosclerotic plaques with hemorrhage considerably contribute to cardiovascular morbidity and mortality. Calcification is the main characteristic of advanced atherosclerotic lesions and calcified aortic valve disease (CAVD). Lyses of red blood cells and hemoglobin (Hb) release occur in human hemorrhagic complicated lesions. During the interaction of cell-free Hb with plaque constituents, Hb is oxidized to ferric and ferryl states accompanied by oxidative changes of the globin moieties and heme release. Accumulation of both ferryl-Hb and metHb has been observed in atherosclerotic plaques. The oxidation hotspots in the globin chain are the cysteine and tyrosine amino acids associated with the generation of Hb dimers, tetramers and polymers. Moreover, fragmentation of Hb occurs leading to the formation of globin-derived peptides. A series of these pro-atherogenic cellular responses can be suppressed by hydrogen sulfide (H2S). Since H2S has been explored to exhibit a wide range of physiologic functions to maintain vascular homeostasis, it is not surprising that H2S may play beneficial effects in the progression of atherosclerosis. In the present review, we summarize the findings about the effects of H2S on atherosclerosis and CAVD with a special emphasis on the oxidation of Hb/heme in atherosclerotic plaque development and vascular calcification.

Incidence and Outcomes of Advanced Heart Failure in Adults With Congenital Heart Disease

BACKGROUND

There are limited data about the stage D heart failure (advanced HF) in adults with congenital heart disease. Our study objectives were (1) to determine the incidence of new-onset advanced HF in patients and the relationship between advanced HF and all-cause mortality and (2) to determine the relationship between therapies for advanced HF and all-cause mortality.

METHODS

Retrospective cohort study of adults with congenital heart disease at Mayo Clinic (2003-2019). We defined advanced HF using the European Society of Cardiology diagnostic criteria for advanced HF. Therapies received by the patients with advanced HF were classified into 3 mutually exclusive groups (treatment pathways): (1) conventional cardiac intervention, (2) transplant listing, and (3) palliative care.

RESULTS

Of 5309 patients without advanced HF at baseline assessment, 432 (8%) developed advanced HF during follow-up (1.1%/y), and the incidence of advanced HF was higher in patients with severe or complex congenital heart disease. Onset of advanced HF was associated with 6-fold increase in the risk of mortality. Conventional cardiac intervention was associated with significantly higher risk of mortality as compared to transplant listing. The longer the interval from the initial onset of advanced HF to transplant evaluation, the lower the odds of being listed for transplant.

CONCLUSIONS

Based on these data, we postulate that early identification of patients with advanced HF, and a timely referral for transplant evaluation (instead of conventional cardiac intervention) may offer the best chance of survival for these critically ill patients. Further studies are required to validate this postulation.

Sacubitril/Valsartan in Patients With Heart Failure and Concomitant End-Stage Kidney Disease

Background

Heart failure with reduced ejection fraction (HFrEF) is a chronic disease with substantial mortality. Management of HFrEF has seen significant breakthrough after the launch of neprilysin inhibitor. The PARADIGM‐HF (Prospective Comparison of ARNI with ACEI to Determine Impacton Global Mortality and Morbidity in Heart Failure) trial showed that sacubitril/valsartan significantly reduces HFrEF mortality and the heart failure hospitalization rate. However, in patients with advanced kidney disease, who have the highest prevalence of heart failure, the efficacy and safety of sacubitril/valsartan remains uncertain. We aim to study the efficiency of sacubitril/valsartan in patients with end‐stage kidney disease.

Methods and Results

Heart function was screened by echocardiogram among all patients with end‐stage kidney disease in 2 hospitals. Patients with HFrEF received either sacubitril/valsartan or conventional treatment. Fifteen echocardiographic parameters were compared before and after treatment. After 1‐year sacubitril/valsartan treatment, parameters of systolic (left ventricular ejection fraction 31.3% to 45.1%, P<0.0001; left ventricular end‐systolic volume 95.7 to 70.1 mL, P=0.006; left ventricular internal diameter at end‐systole phase 47.2 to 40.1 mm, P=0.005), and diastolic (E/A ratio 1.3 to 0.8, P=0.009; E/Med e' ratio 25.3 to 18.8, P=0.010) function improved in patients with HFrEF and end‐stage kidney disease. These parameters were unchanged in the conventional treatment group. Serum potassium did not increase in the sacubitril/valsartan group.

Conclusions

Sacubitril/valsartan improves left ventricular systolic and diastolic function in patients with HFrEF and end‐stage kidney disease.

Celastrol: A Promising Agent Fighting against Cardiovascular Diseases

Cardiovascular diseases (CVD) are leading causes of morbidity and mortality worldwide; therefore, seeking effective therapeutics to reduce the global burden of CVD has become increasingly urgent. Celastrol, a bioactive compound isolated from the roots of the plant Tripterygium wilfordii (TW), has been attracting increasing research attention in recent years, as it exerts cardiovascular treatment benefits targeting both CVD and their associated risk factors. Substantial evidence has revealed a protective role of celastrol against a broad spectrum of CVD including obesity, diabetes, atherosclerosis, cerebrovascular injury, calcific aortic valve disease and heart failure through complicated and interlinked mechanisms such as direct protection against cardiomyocyte hypertrophy and death, and indirect action on oxidation and inflammation. This review will mainly summarize the beneficial effects of celastrol against CVD, largely based on in vitro and in vivo preclinical studies, and the potential underlying mechanisms. We will also briefly discuss celastrol’s pharmacokinetic limitations, which hamper its further clinical applications, and prospective future directions.

The effects of curcumin-containing supplementations on inflammatory markers and lipid profiles in patients with chronic kidney diseases: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

An evaluation the effects of curcumin on inflammatory markers and lipid profiles among patients with chronic kidney diseases (CKD).

METHODS

The electronic databases such as PubMed, and Scopus were searched systematically up until 12 December 2021. To evaluate the quality of the included studies, the Cochrane risk-of-bias tool for randomized trials was utilized. Likewise, data pooling was performed using a random effects model, also called a variance components model. Also, the findings were calculated as weighted mean difference (WMD) with a 95% confidence interval (CI).

RESULTS

In the end, this meta-analysis comprised a total number of nine studies. Curcumin intake significantly reduced total cholesterol (TC) (WMD=-13.77 mg/dL; 95% CI, -26.77, -0.77; p=0.04) and tumor necrosis factor alpha (TNF-α) (WMD=-18.87 pg/mL; 95% CI, -28.36, -9.38; p<0.001) compared with controls. The results did not confirm the significant effect of curcumin intake on triglyceride (TG) (WMD=-6.37 mg/dL; 95% CI, -26.59, 13.85; p=0.54), low-density lipoproteins (LDL-C) (WMD=-5.65 mg/dL; 95% CI, -20.81, 9.50; p=0.46), high-density lipoprotein (HDL-C) (WMD=0.16 mg/dL; 95% CI, -2.55, 2.88; p=0.91), and C-reactive protein (CRP) (WMD=-0.13 mg/L; 95% CI, -3.25, 3.30; p=0.93).

CONCLUSIONS

Our study showed that curcumin significantly impacts TC and TNF levels in CKD patients.

Oral Cholecalciferol Supplementation in Sahara Black People with Chronic Kidney Disease Modulates Cytokine Storm, Oxidative Stress Damage and Athero-Thromboembolic Risk

The 25-hydroxyvitamin D3 (25OHD3) deficiency in chronic kidney disease (CKD) is associated with immune system dysfunction (pro-inflammatory cytokines storm) through macrophages renal infiltration, oxidative stress (OxS) damage and athero-thromboembolic risk. Conversely, cholecalciferol supplementation (25OHD-S) prevents kidney fibrosis by inhibition of vascular calcification and nephrotic apoptosis (nephrons reduction). The objective of this study was to investigate the pleiotropic effects of 25OHD-S on immunomodulation, antioxidant status and in protecting against thromboembolic events in deficiency CKD Black and White individuals living in the Southern Sahara (SS). The oral 25OHD-S was evaluated in 60,000 IU/month/36 weeks versus in 2000 IU/day/24 weeks in Black (n = 156) and White (n = 150). Total serum vitamin D was determined by liquid chromatography-tandem mass spectrometry. All biomarkers of pro-inflammatory cytokines (PIC) were assessed by ELISA tests. OxS markers were assessed by Randox kits. Homocysteine and lipoproteine (a) were evaluated by biochemical methods as biomarkers of atherothromboembolic risk. All statistical analyses were performed with Student’s t-test and one-way ANOVA. The Pearson test was used to calculate the correlation coefficient. The means will be significantly different at a level of p value < 0.05. Multiple logistic regressions were performed using Epi-info and Statview software. Vitamin D deficiency alters the PIC profile, OxS damage and atherothrombogenic biomarkers in both SS groups in the same manner; however, these disorders are more acute in Black compared to White SS individuals. The results showed that the serum 25OHD3 concentrations became normal (>75 nmol/L or >30 ng/mL) in the two groups. We have shown that the dose and duration of 25OHD-S treatment are not similar in Black SS residents compared to White SS subjects, whilst the same inhabit the south Sahara environment. It appears that a high dose intermittent over a long period (D60: 36 weeks) was more efficient in Black people; while a lower dose for a short time is sufficient (D2: 24 weeks) in their White counterparts. The oral 25OHD-S attenuates PIC overproduction and OxS damage, but does not reduce athero-thromboembolic risk, particularly in Black SS residents.

Role of oxidative stress in calcific aortic valve disease and its therapeutic implications

Calcific aortic valve disease (CAVD) is the end result of active cellular processes that lead to the progressive fibrosis and calcification of aortic valve leaflets. In western populations, CAVD is a significant cause of cardiovascular morbidity and mortality, and in the absence of effective drugs, it will likely represent an increasing disease burden as populations age. As there are currently no pharmacological therapies available for preventing, treating, or slowing the development of CAVD, understanding the mechanisms underlying the initiation and progression of the disease is important for identifying novel therapeutic targets. Recent evidence has emerged of an important causative role for reactive oxygen species (ROS)-mediated oxidative stress in the pathophysiology of CAVD, inducing the differentiation of valve interstitial cells into myofibroblasts and then osteoblasts. In this review, we focus on the roles and sources of ROS driving CAVD and consider their potential as novel therapeutic targets for this debilitating condition.

Pediatric Mineral and Bone Disorder of Chronic Kidney Disease and Cardiovascular Disease

Chronic kidney disease is common and causes significant morbidity including shortened lifespans and decrease in quality of life for patients. The major cause of mortality in chronic kidney disease is cardiovascular disease. Cardiovascular disease within the chronic kidney disease population is closely tied with disordered calcium and phosphorus metabolism and driven in part by renal bone disease. The complex nature of renal, bone, and cardiovascular diseases was renamed as mineral and bone disorder of chronic kidney disease to encompass how bone disease drives vascular calcification and contributes to the development of long-term cardiovascular disease, and recent data suggest that managing bone disease well can augment and improve cardiovascular disease status. Pediatric nephrologists have additional obstacles in optimal mineral and bone disorder of chronic kidney disease management such as linear growth and skeletal maturation. In this article, we will discuss cardiovascular and bone diseases in chronic kidney disease and end-stage kidney disease patients with a focus on pediatric issues and concerns.

Insights Into the Role of Mitochondria in Vascular Calcification

Vascular calcification (VC) is a growing burden in aging societies worldwide, and with a significant increase in all-cause mortality and atherosclerotic plaque rupture, it is frequently found in patients with aging, diabetes, atherosclerosis, or chronic kidney disease. However, the mechanism of VC is still not yet fully understood, and there are still no effective therapies for VC. Regarding energy metabolism factories, mitochondria play a crucial role in maintaining vascular physiology. Discoveries in past decades signifying the role of mitochondrial homeostasis in normal physiology and pathological conditions led to tremendous advances in the field of VC. Therapies targeting basic mitochondrial processes, such as energy metabolism, damage in mitochondrial DNA, or free-radical generation, hold great promise. The remarkably unexplored field of the mitochondrial process has the potential to shed light on several VC-related diseases. This review focuses on current knowledge of mitochondrial dysfunction, dynamics anomalies, oxidative stress, and how it may relate to VC onset and progression and discusses the main challenges and prerequisites for their therapeutic applications.

Vascular Calcification: New Insights Into BMP Type I Receptor A

Vascular calcification (VC) is a complex ectopic calcification process and an important indicator of increased risk for diabetes, atherosclerosis, chronic kidney disease, and other diseases. Therefore, clarifying the pathogenesis of VC is of great clinical significance. Numerous studies have shown that the onset and progression of VC are similar to bone formation. Members of the bone morphogenetic protein (BMP) family of proteins are considered key molecules in the progression of vascular calcification. BMP type I receptor A (BMPR1A) is a key receptor of BMP factors acting on the cell membrane, is widely expressed in various tissues and cells, and is an important “portal” for BMP to enter cells and exert their biological effect. In recent years, many discoveries have been made regarding the occurrence and treatment of ectopic ossification-related diseases involving BMP signaling targets. Studies have confirmed that BMPR1A is involved in osteogenic differentiation and that its high expression in vascular endothelial cells and smooth muscle cells can lead to vascular calcification. This article reviews the role of BMPR1A in vascular calcification and the possible underlying molecular mechanisms to provide clues for the clinical treatment of such diseases.

Extracellular Vesicles From LPS-Treated Macrophages Aggravate Smooth Muscle Cell Calcification by Propagating Inflammation and Oxidative Stress

Background: Vascular calcification (VC) is a cardiovascular complication associated with a high mortality rate among patients with diseases such as atherosclerosis and chronic kidney disease. During VC, vascular smooth muscle cells (VSMCs) undergo an osteogenic switch and secrete a heterogeneous population of extracellular vesicles (EVs). Recent studies have shown involvement of EVs in the inflammation and oxidative stress observed in VC. We aimed to decipher the role and mechanism of action of macrophage-derived EVs in the propagation of inflammation and oxidative stress on VSMCs during VC.

Methods: The macrophage murine cell line RAW 264.7 treated with lipopolysaccharide (LPS-EK) was used as a cellular model for inflammatory and oxidative stress. EVs secreted by these macrophages were collected by ultracentrifugation and characterized by transmission electron microscopy, cryo-electron microscopy, nanoparticle tracking analysis, and the analysis of acetylcholinesterase activity, as well as that of CD9 and CD81 protein expression by western blotting. These EVs were added to a murine VSMC cell line (MOVAS-1) under calcifying conditions (4 mM Pi—7 or 14 days) and calcification assessed by the o-cresolphthalein calcium assay. EV protein content was analyzed in a proteomic study and EV cytokine content assessed using an MSD multiplex immunoassay.

Results: LPS-EK significantly decreased macrophage EV biogenesis. A 24-h treatment of VSMCs with these EVs induced both inflammatory and oxidative responses. LPS-EK-treated macrophage-derived EVs were enriched for pro-inflammatory cytokines and CAD, PAI-1, and Saa3 proteins, three molecules involved in inflammation, oxidative stress, and VC. Under calcifying conditions, these EVs significantly increase the calcification of VSMCs by increasing osteogenic markers and decreasing contractile marker expression.

Conclusion: Our results show that EVs derived from LPS-EK–treated-macrophages are able to induce pro-inflammatory and pro-oxidative responses in surrounding cells, such as VSMCs, thus aggravating the VC process.

Oxidative Stress Related to Plasmalemmal and Mitochondrial Phosphate Transporters in Vascular Calcification

Inorganic phosphate (Pi) is essential for maintaining cellular function but excess of Pi leads to serious complications, including vascular calcification. Accumulating evidence suggests that oxidative stress contributes to the pathogenic progression of calcific changes. However, the molecular mechanism underlying Pi-induced reactive oxygen species (ROS) generation and its detrimental consequences remain unclear. Type III Na⁺-dependent Pi cotransporter, PiT-1/-2, play a significant role in Pi uptake of vascular smooth muscle cells. Pi influx via PiT-1/-2 increases the abundance of PiT-1/-2 and depolarization-activated Ca²⁺ entry due to its electrogenic properties, which may lead to Ca²⁺ and Pi overload and oxidative stress. At least four mitochondrial Pi transporters are suggested, among which the phosphate carrier (PiC) is known to be mainly involved in mitochondrial Pi uptake. Pi transport via PiC may induce hyperpolarization and superoxide generation, which may lead to mitochondrial dysfunction and endoplasmic reticulum stress, together with generation of cytosolic ROS. Increase in net influx of Ca²⁺ and Pi and their accumulation in the cytosol and mitochondrial matrix synergistically increases oxidative stress and osteogenic differentiation, which could be prevented by suppressing either Ca²⁺ or Pi overload. Therapeutic strategies targeting plasmalemmal and mitochondrial Pi transports can protect against Pi-induced oxidative stress and vascular calcification.

A Potential Role of Ethosuximide and Pentoxifylline in Relieving Abdominal Pain in Irritable Bowel Syndrome Patients Treated with Mebeverine: A Randomized, Double-Blind, Placebo-Controlled Trial

Background and Purpose

Irritable bowel syndrome (IBS) is defined as an association of chronic abdominal pain with bowel habit abnormalities, without clear organic dysfunction. T-type calcium channels and low-grade mucosal inflammation are linked to abdominal pain; however, medical treatments for IBS abdominal pain are largely ineffective. In this study, we investigated if pentoxifylline (PTX) and ethosuximide could potentially alleviate abdominal pain in patients with IBS treated with mebeverine.

Methods

We recruited 150 patients from Tanta University Hospital to this randomized, prospective, and double blinded study. Patients were randomly allocated to three groups (n = 50). Group 1 (mebeverine) received 135 mg mebeverine three times/day (t.i.d). Group 2 (ethosuximide group) received 135 mg mebeverine t.i.d plus 250 mg ethosuximide twice daily (b.i.d) and group 3 (PTX group) received 135 mg mebeverine t.i.d plus 400 mg PTX b.i.d. Patients were assessed by a gastroenterologist at baseline and 6 months after therapy. Serum interleukin-8 (IL-8), IL-6, tumor necrosis-α (TNF-α), fecal myeloperoxidase, and fecal neutrophil gelatinase associated lipocalin (NGAL) levels were measured before and after therapy. The numeric pain rating scale (NRS) was also assessed before and after therapy.

Primary Outcomes

Reduced NRS scores and abdominal pain relief.

Secondary Outcomes

Decreased inflammatory biomarkers.

Results

After 6 months, groups 2 and 3 showed a significantly greater reduction in serum IL-8, IL-6, TNF-α, fecal myeloperoxidase, and fecal NGAL levels when compared to group 1 after therapy. Both groups 2 and 3 showed significant reductions in NRS scores when compared to the group 1.

Conclusion

Ethosuximide and PTX may be promising, novel adjunct drugs to antispasmodics for relieving abdominal pain in patients with IBS.

Trial Registration

Identifier: NCT04217733.

The bi-directional effect of markers of inflammation and a decrease in glomerular filtration rate in chronic kidney disease

The aim of the study was to analyze and evaluate the relationship between the cytokine profile, C-reactive blood protein, fibrinogen, and glomerular filtration rate in patients with chronic kidney disease. The study involved individuals (n = 816) with chronic kidney disease (CKD) from the 1st to 5th stage of the disease, aged 20 to 76 years. The male to female ratio was 48% and 52%, respectively. All examined individuals underwent a comprehensive clinical and laboratory study evaluating the concentration of interleukins (IL, IL-10, IL-6, TNF-α) and acute phase inflammation proteins (C-reactive protein, fibrinogen) in the blood. CKD categories were evaluated by glomerular filtration rate (GFR), which was calculated using the CKD-EPI formula (Chronic Kidney Disease Epidemiology Collaboration). In individuals with CKD, significantly high concentrations of IL-10 and IL-6 were observed at stage 3b of the disease. Systolic blood pressure, median TNF-α, blood fibrinogen, and the number of individuals with high CRP were significant at stage 4 of CKD. A statistically significant correlation was found between the estimated GFR with the level of IL-6, CRP, blood fibrinogen at the 2nd stage of the disease and the concentration of IL-10 at 3b and TNF-α at the 4th stage of CKD. At the initial stage of CKD, there is a significant relationship between a decrease in estimated GFR and an increase in the level of IL-6, IL-10, TNF-α, as well as an increase in CRP and blood fibrinogen, which becomes pronounced at stages 3b and 4 of CKD.

Causal Association Between Tea Consumption and Kidney Function: A Mendelian Randomization Study

Background

Causal research concerning the consumption of tea and the risk of chronic kidney disease (CKD) is limited. This study identified the potential causal effects of tea intake on CKD, the estimated glomerular filtration rate (eGFR), and albuminuria.

Methods

Genome-wide association studies (GWASs) from UK Biobank were able to identify single-nucleotide polymorphisms (SNPs) associated with an extra cup of tea each day. The summary statistics for the kidney function from the CKDGen consortium include 11,765 participants (12,385 cases of CKD) and 54,116 participants for the urinary albumin-to-creatinine ratio who were mostly of European descent. A two-sample Mendelian randomization (MR) analysis was performed to test the relationship between the selected SNPs and the risk of CKD.

Results

A total of 2,672 SNPs associated with tea consumption (p < 5 × 10^-8) were found, 45 of which were independent and usable in CKDGen. Drinking more cups of tea per day indicates a protective effect for CKD G3-G5 [odds ratio (OR) = 0.803; p = 0.004] and increases eGFR (β = 0.019 log ml/min/1.73 m² per cup per day; p = 2.21 × 10^-5). Excluding two SNPs responsible for directional heterogeneity (Cochran Q p = 0.02), a high consumption of tea was also negatively correlated with a lower risk of albuminuria (OR = 0.758; p = 0.002).

Conclusion

From the perspective of genes, causal relationships exist between daily extra cup of tea and the reduced risk of CKD and albuminuria and increased eGFR.

Role of Nox4 in High Calcium-Induced Renal Oxidative Stress Damage and Crystal Deposition

Aims: We aimed at exploring the role of nicotinamide adenine dinucleotide phosphate oxidase subunit 4 (Nox4) in the regulation of hypercalciuria-induced renal oxidative damage and crystal depositions. Results: High calcium activated Nox4 expression through protein kinase C (PKC). Downregulation of Nox4 expression attenuated hypercalciuria-induced osteoblast-associated protein expression, oxidative stress injury, and crystal deposition in rat kidneys of 1,25-dihydroxyvitamin D3 (VitD) urolithiasis model. Further, calcium-induced activation of mitogen-activated protein kinase (MAPK), overexpression of osteoblast-associated protein, oxidative stress injury, apoptosis, and calcium salt deposition in normal rat kidney epithelial-like (NRK-52E) cells were reversed by downregulating Nox4 expression but were enhanced by upregulating Nox4 expression in vitro. Moreover, calcium-induced increases of osteoblast-associated protein expression were attenuated by the c-Jun-N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) inhibitors. Innovation: Our results demonstrated the effect of Nox4 in the pathological process of kidney stones in in vitro and in vivo studies for the first time. Calcium aggravates renal oxidative stress injury and crystal deposition by activating the Nox4-related reactive oxygen species (ROS)-ERK/JNK pathway in the rat kidney. This study is expected to provide a new theoretical basis for the prevention and treatment of kidney stones. Conclusion: Nox4-derived ROS induced by calcium through PKC caused oxidative stress damage and apoptosis in renal tubular epithelial cells; in addition, Nox4-derived ROS induced by calcium mediated abnormal activation of the bone morphogenetic protein 2 (BMP2) signaling pathway through the MAPK signaling pathway, which induced renal tubular epithelial cells to transdifferentiate into osteoblast-like cells, resulting in the formation of a kidney stone. Antioxid. Redox Signal. 36, 15-38.

NRF2-suppressed vascular calcification by regulating the antioxidant pathway in chronic kidney disease

Vascular calcification (VC), in which vascular smooth muscle cells (VSMCs) undergo differentiation and osteogenic transition, is a common complication of chronic kidney disease (CKD). Recent findings show that nuclear factor-erythroid-2-related factor 2 (NRF2) is an evolutionarily conserved antioxidant and beneficial in preventing vascular senescence and calcification. The roles of NRF2 in the initiation and progression of VC in CKD still need further investigation. CKD-associated VC model rats exhibited significant upregulation of NRF2, NAD(P)H: quinone oxidoreductase-1 (NQO1), osteogenic markers such as alkaline phosphatase (ALP), runt-related transcription factor-2 (RUNX2) and osteopontin (OPN), and β-catenin compared to CKD rats. Immunohistochemistry further verified these results. In addition, rat aortic VSMCs were isolated and subjected to four treatments: normal control, phosphorus-induced (Pi), Pi + NRF2 activator DMF, and Pi + NRF2 inhibitor ML385. The reactive oxygen species (ROS) generation, malondialdehyde (MDA) content, and calcium deposition of the four treatments were determined. The mRNA and protein expression levels of NRF2, NQO1, and haem oxygenase 1 (HO1) and the osteogenic markers ALP, Runx1, OPN, bone morphogenetic protein 2 (BMP2), and β-catenin were quantified by RT-PCR and western blotting. VSMC apoptosis was calculated by flow cytometry. The in vitro results suggested that intracellular oxidative stress and calcification were closely associated with NRF2 activity and that the activation of NRF2 could significantly suppress osteogenic transition and apoptosis in VSMCs. Thus, this study indicated that the NRF2-related antioxidant pathway can positively respond to and protect against the initiation and progression of VC in CKD by reducing oxidative stress. This study may contribute insights facilitating the application of the NRF2 antioxidative system as a therapeutic treatment for vascular diseases such as CKD.

Diabetic mellitus, vascular calcification and hypoxia: A complex and neglected tripartite relationship

DM (diabetic mellitus) and its common vascular complications VC (vascular calcification), are increasingly harmful to human health. In recent years, the research on the relationship between DM and VC is also deepening. Hypoxia, as one of the pathogenic factors of many disease models, is also closely related to the occurrence of DM and VC. There are some studies on the role of hypoxia in the pathogenesis of DM and VC respectively, but no one has made an in-depth summary of the systematic connection between hypoxia, DM and VC. Therefore, what we want to review in this article are the relationship between DM, VC and hypoxia, respectively, as well as the role of hypoxia in the development of DM and VC, which has little concern but is a novel and potentially target that may provide some new ideas for the prevention and treatment of DM, VC, especially diabetic VC.

Predictors of coronary artery calcification and its association with cardiovascular events in patients with chronic kidney disease

OBJECTIVE

To investigate the predictors of coronary artery calcification (CAC) and its association with cardiovascular events (CVE) in patients with stage 3-5 chronic kidney disease (CKD).

METHOD

Two hundred ninety CKD patients in our nephrology department were enrolled from 2018 to May 2019. The levels of matrix Gla protein (MGP) and interleukin 6 (IL-6) were measured via enzyme-linked immunosorbent assay (ELISA) method in 131 CKD patients of all. CAC was evaluated via computed tomography (CT). The covariate factors were analyzed by binary logistic regression analysis. We conducted the visits to explore the prevalence of CVE in 276 CKD patients, and covariate factors were analyzed by Cox proportional hazard model.

RESULTS

The prevalence of CAC was up to 57.93%. We found that age, diabetes mellitus, hyperphosphatemia, dialysis duration, and the neutrophil-lymphocyte ratio (NLR) were positively associated with CAC in all patients. In 131 patients, we demonstrated that higher IL-6 and lower MGP levels were associated with CAC. A Cox proportional hazard model demonstrated that moderate to severe CAC was correlated with an increased risk for CVE [Hazard Ratio (HR): 7.250; 95% confidence interval (CI): 3.192-16.470], and a higher MGP level was associated with a reduced risk for CVE (HR: 0.340; 95% CI: 0.124-0.933).

CONCLUSIONS

The prevalence of CAC in patients with CKD is a significant issue. Older age, hyperphosphatemia, dialysis duration, diabetes mellitus, IL-6, and the NLR are associated with CAC. In addition, higher MGP levels represent protective factor for CAC. Moderate to severe CAC, and lower MGP levels are associated with an increased risk for CVE. Abbreviations: AGEs: Advanced glycosylation end products; CAC: Coronary artery calcification; CACS: Coronary artery calcification score; Ca: Calcium; CI: confidence interval; CKD: Chronic kidney disease; CVE: Cardiovascular events; CT: Computed tomography; ELISA: Enzyme-linked immunosorbent assay; Hb: hemoglobin; HR: Hazard ratio; hs-CRP: high-sensitivity C-reactive protein; IL-6: Interleukin 6; iPTH: Intact parathyroid hormone; Mg: Magnesium; MGP: Matrix Gla protein; NF-κB: nuclear factor-kappa gene binding; NRL: Neutrophil-lymphocyte ratio; Runx2: Runt-related transcription factor 2; RRT: Renal replacement therapy; P: Phosphorus; Scr: Serum creatinine; TNF--alpha: Tumor necrosis factor--alpha; TC: Total cholesterol; TG: Triglyceride; VSMC: vascular smooth muscle cel.

Tolerance of peritoneal and residual renal function to intraperitoneal gadolinium-based agents: An animal experimental study of magnetic resonance peritoneography

BACKGROUND

MR (Magnetic resonance) peritoneography is sensible for continuous ambulatory peritoneal dialysis (CAPD)-related complications, which could offer excellent soft-tissue contrast and allows a multiplanar imaging evaluation of complications. However, there is no study about the optimal concentration of the gadolinium-based agents nor the side effects of gadolinium-based agents on peritoneum and residual renal function.

METHOD

Five different groups of uremic rats and two groups of normal rats were injected with a 40-ml mixture of peritoneal dialysate and gadolinium-based agents at varying concentrations prior to MR peritoneography. Thereafter, MR image obtained was evaluated by two experienced radiologists blinded to the concentrations. Peritoneal morphology and thickness of the uremic rats were also assessed using hematoxylin and eosin and Masson staining. Residual renal function was evaluated using serum creatinine levels and hematoxylin and eosin (HE) staining of pathological kidney sections.

RESULTS AND CONCLUSION

The gadolinium-based agents used in this experiment have no significant effect on residual renal function. There is no obvious difference in the image quality at the different gadolinium-based agents concentration. Due to the adverse effects of gadolinium-based agents in the previous studies, we suggest reducing the dose of gadolinium-based agents during MR peritoneography to the lowest limits.

Pentoxifylline, a nonselective phosphodiesterase inhibitor, in adjunctive therapy in patients with irritable bowel syndrome treated with mebeverine

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal condition marked by chronic bowel pain or discomfort, as well as changes in abdominal motility. Despite its worldwide prevalence and clinical impact, the cause of IBS is unknown. Inflammation could play a fundamental role in the development of IBS. The aim of this study was to examine whether pentoxifylline, a competitive nonselective phosphodiesterase inhibitor, is useful in alleviating abdominal pain in IBS patients treated with mebeverine.

METHODS

A randomized, controlled, and prospective clinical study that included 50 outpatients who met the inclusion criteria for IBS. Patients are allocated randomly into two groups (n = 25). Group 1 (mebeverine group) received mebeverine 135 mg three times daily (t.i.d) for three months. Group 2 (pentoxifylline group) received mebeverine 135 mg t.i.d and pentoxifylline 400 mg two times daily for three months. Patients were assessed by a gastroenterologist at baseline and three months after the medication had been started. The serum levels of interleukin-6, interleukin-8 and tumor necrosis factor-alpha, fecal Neutrophil Gelatinase Associated Lipocalin (NGAL), and fecal myeloperoxidase were measured at the start and after three months of therapy. The Numeric Pain Rating scale (NRS) was assessed at baseline and after therapy.

RESULTS

the pentoxifylline group showed a significant decrease in the level of measured biomarkers and a significant decrease in NRS.

CONCLUSION

Pentoxifylline could be a promising adjuvant anti-inflammatory drug in the treatment of abdominal pain in IBS patients treated with mebeverine.

MicroRNAs in Valvular Heart Diseases: Biological Regulators, Prognostic Markers and Therapeutical Targets

miRNAs have recently attracted investigators’ interest as regulators of valvular diseases pathogenesis, diagnostic biomarkers, and therapeutical targets. Evidence from in-vivo and in-vitro studies demonstrated stimulatory or inhibitory roles in mitral valve prolapse development, aortic leaflet fusion, and calcification pathways, specifically osteoblastic differentiation and transcription factors modulation. Tissue expression assessment and comparison between physiological and pathological phenotypes of different disease entities, including mitral valve prolapse and mitral chordae tendineae rupture, emerged as the best strategies to address miRNAs over or under-representation and thus, their impact on pathogeneses. In this review, we discuss the fundamental intra- and intercellular signals regulated by miRNAs leading to defects in mitral and aortic valves, congenital heart diseases, and the possible therapeutic strategies targeting them. These miRNAs inhibitors are comprised of antisense oligonucleotides and sponge vectors. The miRNA mimics, miRNA expression vectors, and small molecules are instead possible practical strategies to increase specific miRNA activity. Advantages and technical limitations of these new drugs, including instability and complex pharmacokinetics, are also presented. Novel delivery strategies, such as nanoparticles and liposomes, are described to improve knowledge on future personalized treatment directions.

Detection of Herbal Combinations and Pharmacological Mechanisms of Clinical Prescriptions for Coronary Heart Disease Using Data Mining and Network Pharmacology

Though widely used in the treatment of coronary heart disease (CHD), the mechanism of traditional Chinese medicine (TCM) is still unclear because of its complex prescription rules. This study prospectively collected 715 prescriptions of TCM for the treatment of CHD. The characteristics of TCM in prescriptions were described and analyzed, and the rules of prescriptions were analyzed by using association rules. Frequency statistics showed that the high-frequency herbs with a frequency of more than 60% were Gan-cao, Huang-qi, Dang-gui, Chuan-xiong, Yan-hu-suo, and San-qi. The high-frequency herb combinations were summarized by using association rules. By using the method of the “Top N groups” to excavate the empirical prescriptions, the basic prescriptions for treating CHD were summarized. We named the intersection herbs of the basic prescriptions and the high frequency herbs as the core herbal prescription. To explore the possible mechanisms underlying the anti-CHD effect of the core herbal prescription, the bioactive components of core herbal prescription and their targets were screened out by using network pharmacology. Molecular docking was performed between the bioactive components and core targets. A total of 28 potential active ingredients and 5 core targets were identified for the treatment of CHD with core herbal prescription. The enrichment analysis results indicated that the mechanism of action mainly involved neuroactive ligand-receptor interaction and calcium signaling pathway. The commonly used herbal pairs for CHD with qi deficiency and blood stasis syndrome were Huang-qi and Dang-gui. The mechanism of action of common herbal pairs was also studied by network pharmacology. This study summarized the prescription rule of TCM in the treatment of CHD and may provide a new idea for the treatment of CHD.