Calcification In Chronic Kidney Disease Research Articles

The functional role of cellular senescence during vascular calcification in chronic kidney disease.

Vascular calcification (VC) has emerged as a key predictor of cardiovascular events in patients with chronic kidney disease (CKD). In recent years, an expanding body of research has put forth the concept of accelerated vascular aging among CKD patients, highlighting the significance of vascular cells senescence in the process of VC. Within the milieu of uremia, senescent vascular endothelial cells (VECs) release extracellular microvesicles (MV) that promote vascular smooth muscle cells (VSMCs) senescence, thereby triggering the subsequent osteogenic phenotypic switch and ultimately contributing to the VC process. In addition, senescent vascular progenitor or stem cells with diminished ability to differentiate into VECs and VSMCS, compromise the repair of vascular integrity, on the other hand, release a cascade of molecules associated with senescence, collectively known as the senescence-associated secretory phenotype (SASP), perpetuating the senescence phenomenon. Furthermore, SASP triggers the recruitment of monocytes and macrophages, as well as adjacent VECs and VSMCs into a pro-adhesive and pro-inflammatory senescent state. This pro-inflammatory microenvironment niche not only impacts the functionality of immune cells but also influences the differentiation of myeloid immune cells, thereby amplifying the reduced ability to effectively clear senescent cells of senescent macrophages, promoted calcification of VSMCs. The objective of this paper is to provide a comprehensive review of the contribution of vascular cell senescence to the emergence and advancement of VC. Gaining a comprehensive understanding of the involvement of cellular senescence within the vessel wall is pivotal, especially when it comes to its intersection with VC. This knowledge is essential for advancing groundbreaking anti-aging therapies, aiming to effectively mitigate cardiovascular diseases.

Magnesium and Vascular Calcification in Chronic Kidney Disease: Current Insights.

Magnesium (Mg) plays crucial roles in multiple essential biological processes. As the kidneys are the primary organ responsible for maintaining the blood concentration of Mg, people with chronic kidney disease (CKD) may develop disturbances in Mg. While both hyper- and hypomagnesemia may lead to adverse effects, the consequences associated with hypomagnesemia are often more severe and lasting. Importantly, observational studies have shown that CKD patients with hypomagnesemia have greater vascular calcification. Vascular calcification is accelerated and contributes to a high mortality rate in the CKD population. Both in vitro and animal studies have demonstrated that Mg protects against vascular calcification via several potential mechanisms, such as inhibiting the formation of both hydroxyapatite and pathogenic calciprotein particles as well as limiting osteogenic differentiation, a process in which vascular smooth muscle cells in the media layer of the arteries transform into bone-like cells. These preclinical findings have led to several important clinical trials that have investigated the effects of Mg supplementation on vascular calcification in people with CKD. Interestingly, two major clinical studies produced contradictory findings, resulting in a state of equipoise. This narrative review provides an overview of our current knowledge in the renal handling of Mg in health and CKD and the underlying mechanisms by which Mg may protect against vascular calcification. Lastly, we evaluate the strength of evidence from clinical studies on the efficacy of Mg supplementation and discuss future research directions.

An Update on Hypomagnesemia and Hypermagnesemia

Magnesium is an essential element with a pleiotropic role in human biology. Despite tight intestinal and renal regulation of its balance, insufficient intake can finally result in hypomagnesemia, which is a proxy of intracellular deficiency. Conditions such as diabetes, cancer, and infections are often associated with hypomagnesemia, which mostly predicts an unfavorable outcome. The effects of hypomagnesemia can either be direct and include neurological and cardiovascular symptoms or indirect, taking a mechanistic role in inflammation, endothelial dysfunction, and oxidative stress. The indication for intravenous magnesium as a treatment of torsades de pointes and pre-eclampsia is unrefuted, but new indications of peroral or intravenous supplementation, albeit with less supporting evidence, have emerged suggesting, respectively, an attenuation of vascular calcification in chronic kidney disease and improved rate control in atrial fibrillation. Other potential beneficial properties of magnesium, which were claimed by observational data, such as lipid lowering and renal protection, were not, or only partially, investigated in randomized controlled trials. Thus, the role of peroral supplementation of mild chronic asymptomatic hypomagnesemia should be separated from the more targeted prescription of magnesium in specific study populations. (Severe) hypermagnesemia is potentially life-threatening and occurs almost uniformly in subjects with severe renal failure exposed to either supplements or to magnesium-containing cathartics or antacids. Moderate hypermagnesemia is very common in pre-eclamptic women treated with intravenous magnesium. For most (but not all) studied endpoints, mild hypermagnesemia yields a survival benefit. Long-lasting concerns about the potential negative effects of mild hypermagnesemia on bone physiology and structure have so far not been unequivocally demonstrated to be troublesome.

Moderate Iron Deficiency Does Not Potentiate Renal or Cardiac Calcification and Subsequent Tissue Injury in Mouse Models of CKD

Chronic kidney disease (CKD) is a public health challenge that affects over 26 million Americans and many more worldwide. Many develop renal and cardiac calcification, which promotes arterial wall stiffness. These structural changes of the vasculature contribute to hypertension and heart failure, increasing the risk of premature death. Dysregulated iron homeostasis also occurs in many patients with CKD, and iron deficiency and anemia are common complications that are independently associated with CKD progression, cardiovascular disease and all-cause mortality. Furthermore, lower transferrin saturation (TSAT) levels are independently associated with higher coronary artery calcification scores in CKD patients receiving hemodialysis. However, whether iron deficiency and/or anemia directly contribute to the pathogenesis of calcification in CKD is unknown. We examined the effects of iron deficiency on renal and cardiac calcification, and tissue injury in mouse models of CKD. We used a dietary model of progressive CKD: 8-week-old male C57BL/6J mice were fed for 8 weeks a customized 0.2% adenine-rich diet that was either iron-replete (100 ppm iron; “adenine-IR” group) or iron-deficient (4 ppm iron, “adenine-ID” group). Control mice were fed a diet without adenine, but with matching iron content (iron-replete “CTRL-IR” and iron-deficient “CTRL-ID” groups). Compared to CTRL-IR mice, CTRL-ID mice developed widespread tissue iron deficiency and anemia as expected. Surprisingly, despite 8 weeks of low iron diet which led to lower serum iron and worse anemia, adenine-ID mice had similarly high liver iron as adenine-IR mice, similar expression of transferrin receptor 1 (marker of tissue iron deficiency) in kidney or heart, and similarly elevated liver hepcidin mRNA. This suggests that hepcidin induction in this CKD model likely protected tissues from iron depletion, at least on the time scale of the experiment. Calcification in adenine mice was evident but was similar between adenine-ID and adenine-IR mice, as observed by the comparable expression of calcification markers in kidney and heart ( Runx2, Sox9, Opn). Additionally, markers of kidney function (BUN and serum creatinine), kidney injury ( Kim1, Lcn2) and cardiac injury( Myh7) were also comparable between adenine-ID and adenine-IR mice. Inflammation and fibrosis were increased in kidney and heart of adenine mice in general, but once again similar between adenine-ID and adenine-IR mice (serum IL-6, Tnfa, Tgfb Col1a1). We then employed a genetic model of progressive CKD ‒ constitutive Col4a3 −/−mice (Alport syndrome, life expectancy in this model ~11 weeks of age), and fed male mice either an IR or ID diet for 7 weeks. Diets were started in juvenile mice (4-week-old), a strategy known to exacerbate the effect of ID diet on tissue iron deficiency and anemia. Despite this, Alport-ID and Alport-IR mice still displayed similar liver iron levels and liver hepcidin expression. Alport-IR and -ID groups also had comparable renal and cardiac calcification, injury, inflammation and fibrosis. Altogether, our findings in two different mouse models of CKD indicate that moderate iron deficiency does not potentiate renal or cardiac calcification and subsequent tissue injury. Our data suggest that despite causing hypoferremia and anemia, chronically elevated hepcidin in CKD might delay the development of tissue iron deficiency in the liver, kidney and heart, and potentially protect against deleterious vascular changes and subsequent tissue injury.

Regulatory effects of nutritional and metabolic disorders on vascular calcification in chronic kidney disease: a narrative review

Regulatory effects of nutritional and metabolic disorders on vascular calcification in chronic kidney disease: a narrative review

Phosphate Toxicity and Vascular Calcification in Chronic Kidney Disease: A Closer Look Utilizing Transmission Electron Microscopy.

Hyperphosphatemia is independently linked with vascular calcification, cardiovascular disease, bone-mineral disease, progression of renal insufficiency, and all-cause mortality in chronic kidney disease (CKD) and end-stage renal disease (ESRD). The emerging importance of fibroblast growth factor-23 (FGF-23) and its co-factor Klotho play very important roles as phosphaturic hormones; however, phosphate levels rise due to a loss of renal Klotho production and the phosphaturic effects of the FGF-23/Klotho axis. Hyperphosphatemia is also associated with calciphylaxis, acceleration of renal tubulointerstitial disease, renal osteodystrophy, and uremic cardiomyopathy. This review incorporates ultrastructural remodeling of the thoracic aorta to provide a different perspective on vascular calcification. Nine-week-old male heterozygous (mRen2) 27 (Ren2) rat models of hypertension, insulin resistance, vascular oxidative stress and albuminuria are utilized to demonstrate aortic remodeling associated with vascular calcification. Nine-week-old male Zucker obese (fa/fa) rat models are utilized to better understand nephrolith formation. Phosphate homeostasis, toxicity, multiple metabolic and uremic toxicities, renal osteodystrophy, and vascular calcification are also discussed. Additionally, the role of the endothelium, vascular smooth muscle cells, inflammatory monocytes/macrophages and mast cells, pericytes, oxidative stress, hydrogen sulfide, and extraosseous calcification in the kidney are discussed as they relate to CKD, ESRD and calciphylaxis.

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

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. 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. 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. 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.

Redox Metabolism and Vascular Calcification in Chronic Kidney Disease.

Vascular calcification (VC) is a common complication in patients with chronic kidney disease which increases their mortality. Although oxidative stress is involved in the onset and progression of this disorder, the specific role of some of the main redox regulators, such as catalase, the main scavenger of H2O2, remains unclear. In the present study, epigastric arteries of kidney transplant recipients, a rat model of VC, and an in vitro model of VC exhibiting catalase (Cts) overexpression were analysed. Pericalcified areas of human epigastric arteries had increased levels of catalase and cytoplasmic, rather than nuclear runt-related transcription factor 2 (RUNX2). In the rat model, advanced aortic VC concurred with lower levels of the H2O2-scavenger glutathione peroxidase 3 compared to controls. In an early model of calcification using vascular smooth muscle cells (VSMCs), Cts VSMCs showed the expected increase in total levels of RUNX2. However, Cts VMSCs also exhibited a lower percentage of the nucleus stained for RUNX2 in response to calcifying media. In this early model of VC, we did not observe a dysregulation of the mitochondrial redox state; instead, an increase in the general redox state was observed in the cytoplasm. These results highlight the complex role of antioxidant enzymes as catalase by regulation of RUNX2 subcellular location delaying the onset of VC.

Chronic kidney disease mineral bone disorder in childhood and young adulthood: a ‘growing’ understanding

Chronic kidney disease (CKD) mineral and bone disorder (MBD) comprises a triad of biochemical abnormalities (of calcium, phosphate, parathyroid hormone and vitamin D), bone abnormalities (turnover, mineralization and growth) and extra-skeletal calcification. Mineral dysregulation leads to bone demineralization causing bone pain and an increased fracture risk compared to healthy peers. Vascular calcification, with hydroxyapatite deposition in the vessel wall, is a part of the CKD-MBD spectrum and, in turn, leads to vascular stiffness, left ventricular hypertrophy and a very high cardiovascular mortality risk. While the growing bone requires calcium, excess calcium can deposit in the vessels, such that the intake of calcium, calcium- containing medications and high calcium dialysate need to be carefully regulated. Normal physiological bone mineralization continues into the third decade of life, many years beyond the rapid growth in childhood and adolescence, implying that skeletal calcium requirements are much higher in younger people compared to the elderly. Much of the research into the link between bone (de)mineralization and vascular calcification in CKD has been performed in older adults and these data must not be extrapolated to children or younger adults. In this article, we explore the physiological changes in bone turnover and mineralization in children and young adults, the pathophysiology of mineral bone disease in CKD and a potential link between bone demineralization and vascular calcification.Graphical abstractA higher resolution version of the Graphical abstract is available as Supplementary information

Lactobacillus rhamnosus GG aggravates vascular calcification in chronic kidney disease: A potential role for extracellular vesicles

AimsLactobacillus rhamnosus GG (LGG) is a probiotic with great promise in future clinical application, which can significantly promote bone formation. However, the effect of LGG on CKD-related vascular calcification is unclear. In this study, we aimed to investigate the effect of LGG on CKD-related vascular calcification. Materials and methodsAfter 2 weeks of 5/6 nephrectomy, CKD rats received a special diet (4 % calcium and 1.8 % phosphate) combined with 1,25-dihydroxyvitamin D3 to induce vascular calcification. Meanwhile, CKD rats in the LGG group were gavaged orally with LGG (1 × 109 CFU bacteria/day). 16S RNA amplicon sequencing was performed to analyze the effect of LGG treatment on gut microbiota composition. Furthermore, differential ultracentrifugation was utilized to extract EVs. The effects of EVs on vascular calcification were evaluated in rat VSMCs, rat aortic rings, and CKD rat calcification models. In this study, vascular calcification was assessed by microcomputed tomography analysis, alizarin red staining, calcium content determination, and the expression of osteogenic transcription factors RUNX2 and BMP2. Key findingsLGG remarkably aggravated vascular calcification. LGG supplementation significantly altered gut microbiota composition in CKD rats, particularly increasing Lactobacillus. Interestingly, EVs presented a significant promoting effect on the development of calcification. Finally, mechanistic analysis proved that EVs aggravated vascular calcification through PI3K/AKT signaling. SignificanceThese results do not support the supplementation of LGG in CKD-associated vascular calcification patients. Our study presented a fresh perspective on LGG with potential risks and adverse effects. CKD patients should use specific probiotic strains cautiously.

Phosphorus May Induce Phenotypic Transdifferentiation of Vascular Smooth Muscle Cells through the Reduction of microRNA-145.

Phosphorus is a vital element for life found in most foods as a natural component, but it is also one of the most used preservatives added during food processing. High serum phosphorus contributes to develop vascular calcification in chronic kidney disease; however, it is not clear its effect in a population without kidney damage. The objective of this in vivo and in vitro study was to investigate the effect of high phosphorus exposure on the aortic and serum levels of miR-145 and its effect on vascular smooth muscle cell (VSMCs) changes towards less contractile phenotypes. The study was performed in aortas and serum from rats fed standard and high-phosphorus diets, and in VSMCs exposed to different concentrations of phosphorus. In addition, miR-145 silencing and overexpression experiments were carried out. In vivo results showed that in rats with normal renal function fed a high P diet, a significant increase in serum phosphorus was observed which was associated to a significant decrease in the aortic α-actin expression which paralleled the decrease in aortic and serum miR-145 levels, with no changes in the osteogenic markers. In vitro results using VSMCs corroborated the in vivo findings. High phosphorus first reduced miR-145, and afterwards α-actin expression. The miR-145 overexpression significantly increased α-actin expression and partially prevented the increase in calcium content. These results suggest that miR-145 could be an early biomarker of vascular calcification, which could give information about the initiation of the transdifferentiation process in VSMCs.

#4372 TYK2-INDUCED STAT ACTIVATION IS ESSENTIAL FOR VASCULAR PRO-CALCIFIC EFFECTS OF LEUKEMIA INHIBITORY FACTOR

Abstract Background and Aims Hyperphosphatemia in chronic kidney disease (CKD) is closely linked to medial vascular calcification. Phosphate is able to induce pro-inflammatory effects in vascular smooth muscle cells (VSMC), which could actively augment calcification processes. This study investigated the role of the IL-6 family member leukemia inhibitory factor (LIF) during vascular calcification. Method Experiments were performed in primary human aortic VSMCs, ex vivo mouse aortic rings and cholecalciferol treated mice, as well as serum samples from CKD patients and healthy controls. Results Phosphate exposure induced LIF release in VSMCs, while supplementation of LIF aggravated calcification and expression of pro-calcific markers in VSMCs. Silencing of LIF or addition of soluble LIF receptor (LIFR) as putative LIF antagonist ameliorated the pro-calcific effects of phosphate. Similarly, effects of phosphate or LIF were blunted by silencing of LIFR or its coreceptor GP130 in VSMCs. Mechanistically, LIF induced phosphorylation of TYK2, which was required for STAT1/3 activation. TYK2 overexpression augmented VSMC calcification, while silencing of either TYK2 or STAT1/3 ameliorated phosphate- and LIF-induced expression of pro-calcific markers. Pharmacological inhibition of TYK2 ameliorated calcification in VSMCs, mouse aortic rings and mice after cholecalciferol treatment. Furthermore, calcification was ameliorated in TYK2-deficient mouse aortic rings and mice after cholecalciferol overload. In a pilot study, LIFR was reduced in serum from patients with CKD and LIFR levels were associated with serum calcification propensity. Conclusion Vascular calcification is augmented by LIF, which identifies a crucial role of TYK2 in the pro-calcific reprogramming of VSMCs. Inhibition of this signalling axis might be able to reduce the burden of vascular calcification in CKD.

Vascular calcification in CKD: New insights into its mechanisms.

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD) and contributes to an increased risk of cardiovascular morbidity and mortality. However, effective therapies are still unavailable at present. It has been well established that VC associated with CKD is not a passive process of calcium phosphate deposition, but an actively regulated and cell-mediated process that shares many similarities with bone formation. Additionally, numerous studies have suggested that CKD patients have specific risk factors and contributors to the development of VC, such as hyperphosphatemia, uremic toxins, oxidative stress and inflammation. Although research efforts in the past decade have greatly improved our knowledge of the multiple factors and mechanisms involved in CKD-related VC, many questions remain unanswered. Moreover, studies from the past decade have demonstrated that epigenetic modifications abnormalities, such as DNA methylation, histone modifications and noncoding RNAs, play an important role in the regulation of VC. This review seeks to provide an overview of the pathophysiological and molecular mechanisms of VC associated with CKD, mainly focusing on the involvement of epigenetic modifications in the initiation and progression of uremic VC, with the aim to develop promising therapies for CKD-related cardiovascular events in the future.

The effect of chronic kidney disease on tissue formation of in situ tissue-engineered vascular grafts.

Vascular in situ tissue engineering encompasses a single-step approach with a wide adaptive potential and true off-the-shelf availability for vascular grafts. However, a synchronized balance between breakdown of the scaffold material and neo-tissue formation is essential. Chronic kidney disease (CKD) may influence this balance, lowering the usability of these grafts for vascular access in end-stage CKD patients on dialysis. We aimed to investigate the effects of CKD on in vivo scaffold breakdown and tissue formation in grafts made of electrospun, modular, supramolecular polycarbonate with ureido-pyrimidinone moieties (PC-UPy). We implanted PC-UPy aortic interposition grafts (n = 40) in a rat 5/6th nephrectomy model that mimics systemic conditions in human CKD patients. We studied patency, mechanical stability, extracellular matrix (ECM) components, total cellularity, vascular tissue formation, and vascular calcification in CKD and healthy rats at 2, 4, 8, and 12 weeks post-implantation. Our study shows successful in vivo application of a slow-degrading small-diameter vascular graft that supports adequate in situ vascular tissue formation. Despite systemic inflammation associated with CKD, no influence of CKD on patency (Sham: 95% vs CKD: 100%), mechanical stability, ECM formation (Sirius red+, Sham 16.5% vs CKD 25.0%-p:0.83), tissue composition, and immune cell infiltration was found. We did find a limited increase in vascular calcification at 12 weeks (Sham 0.08% vs CKD 0.80%-p:0.02) in grafts implanted in CKD animals. However, this was not associated with increased stiffness in the explants. Our findings suggest that disease-specific graft design may not be necessary for use in CKD patients on dialysis.

BRG1 is involved in vascular calcification in chronic renal disease via autophagy of vascular smooth muscle cells

We aimed to investigate the mechanisms of Brahma related gene 1 (BRG1) in promoting vascular calcification in chronic kidney disease (CKD). The expression of BRG1 was examined in high phosphorus stimulated rat aortic smooth muscle cells (RASMCs) and calcified artery tissues from rat models and hemodialysis patients. Autophagosome formation was measured in high phosphorus stimulated RASMCs with and without BRG1 knock-down. We also detected the coexistence of BGR1 and exosomes, and measured the circulatory levels of BRG1 in the hemodialysis patients. BRG1 promoted the osteogenic transdifferentiation of RASMCs. Silencing BRG1 prevented autophagy from being induced by high phosphorus stimulation in RASMCs. Increased expression of BRG1 was observed in calcified blood vessels. Serum BRG1 level increased in the hemodialysis patients. BRG1 was involved in the development of high phosphorus induced osteogenic phenotype invitro and invivo, and its underlying mechanism might be facilitating autophagy.

Serum sclerostin in vascular calcification in CKD: a meta-analysis

Vascular calcification (VC) is recognized as a predictor of all-cause and CVD mortality in chronic kidney disease (CKD). VC in CKD is possibly associated with serum sclerostin. The study systematically investigated the role of serum sclerostin in VC in CKD. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols, a systematic search was performed of the PubMed, Cochrane Library, and EMBASE databases from inception to 11 November 2022, to identify relevant eligible studies. The data were retrieved, analyzed, and summarized. The hazard ratios (HRs) and odds ratios (ORs) with their corresponding confidence intervals (CIs) were derived and pooled. Thirteen reports (3125 patients) met the inclusion criteria and were included. Sclerostin was associated with the presence of VC (pooled OR = 2.75, 95%CI = 1.81–4.19, p < 0.01) and all-cause mortality (pooled HR = 1.22, 95%CI = 1.19–1.25, p < 0.01) among patients with CKD, but with a decreased risk of cardiovascular events (HR = 0.98, 95%CI = 0.97–1.00, p = 0.02). This meta-analysis suggests that serum sclerostin is associated with VC and all-cause mortality among patients with CKD.

VX-765 ameliorates CKD VSMC calcification by regulating STAT3 activation

BackgroundRecent clinical evidences show that caspase-1 inhibitor-VX-765 attenuates atherosclerosis in ApoE deficient mice. However, there is rarely information about the effect of VX-765 on hyperphosphatemia-induced vascular smooth muscle cells (VSMCs) calcification or vascular calcification in chronic kidney disease (CKD) rats. Here we investigate the effect of VX-765 on vascular calcification in uremia circumstances. MethodsHyperphosphatemia-induced VSMC calcification were evaluated by Alizarin Red S. Aortas from CKD rats which were gavaged with VX-765 were examined for calcification signal using micro-CT. Levels of NLRP3, caspase-1, and GSDMD were measured by quantitative real-time PCR, western blotting, immunofluorescence assay, and immunohistochemistry. ResultsWe demonstrated for the first time that the levels of NLRP3, caspase-1, GSDMD, IL-1β, and IL-18 were up-regulated in hyperphosphatemia-induced calcifying VSMCs. Blockade of caspase-1 activation by VX-765 inhibited pyroptosis-related molecules and VSMC calcification in a concentration-dependent manner in vitro. Further analysis of aortas from calcified CKD rats showed an up-regulation of caspase-1 and GSDMD expression compared with those non-calcified vascular tissue from control rats or with those decreased-calcified vascular tissue from CKD rats treated with 50 mg/kg/d, which indicated that pyroptotic indicators were tightly correlated with CKD arterial calcification. In vitro studies further demonstrated that VX-765 ameliorated hyperphosphatemia-induced VSMCs calcification through inhibiting the STAT3 activation. ConclusionsOur findings indicated that VX-765 could inhibit hyperphosphatemia-induced calcifying VSMCs and ameliorate vascular calcification in CKD rats. VX-765 might be a potential treatment strategy for CKD vascular calcification.

In this Issue

HomeCirculation ResearchVol. 132, No. 4In this Issue Free AccessIn BriefPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessIn BriefPDF/EPUBIn this Issue Originally published16 Feb 2023https://doi.org/10.1161/RES.0000000000000595Circulation Research. 2023;132:397is related toADAR1 Non-Editing Function in Macrophage Activation and Abdominal Aortic AneurysmCirculating Extracellular Vesicle-Propagated microRNA Signature as a Vascular Calcification Factor in Chronic Kidney DiseaseCNP Promotes Antiarrhythmic Effects via Phosphodiesterase 2CNP Promotes Anti-Arrhythmic Effects via Phosphodiesterase 2 (p 400)Download figureDownload PowerPointCachorro et al suggest new targets for treating arrhythmia in heart failure.If a person survives a myocardial infarction they remain at risk of eventual death from heart failure, with arrhythmia and sudden cardiac death being major causes. β-blockers are often used to mitigate arrhythmia in heart failure but have side effects such as hypotension, dizziness and brachycardia due to the heart’s reduced contractile force. In the search for novel targets and treatments, it was discovered that overexpression of the enzyme phosphodiesterase 2 (PDE2), involved in cardiomyocyte contractility among other things, protected mice from arrhythmia and death after infarction. Furthermore, in rats with acute myocardial ischemia, treatment with the vasoactive molecule c-type natriuretic protein (CNP) also reduced arrhythmia. Cachorro and colleagues now show that these two separate findings are in fact linked. Indeed, CNP treatment of mice induced PDE2 to reduce arrhythmia, they found. And, pharmaceutical or genetic inhibition of PDE2 activity, prevented CNP’s antiarrhythmic effects. Similar results were found in cultured cells, where CNP suppressed arrhythmogenic activity in mouse and human cardiomyocytes but not if PDE2 was inhibited. Together the results point to the CNP-PDE2 pathway as a possible target for new heart failure medications, say the team.ADAR1 Non-Editing Function in Macrophage Activation and Abdominal Aortic Aneurysm (p e78)Download figureDownload PowerPointMacrophage ADAR1 is a key driver of abdominal aortic aneurysm, report Cai et al.Abdominal aortic aneurysm (AAA) is a life-threatening chronic inflammatory disorder in which the wall of the vessel becomes progressively weakened leading to its localized bulging and potential rupture. It causes around 10,000 deaths annually in the US alone and with the exception of surgery there are no targeted treatments. An RNA processing protein called ADAR1, with RNA-editing and non-editing functions, has been linked to the disease, being found at raised levels in mouse and patient AAA lesions. Deletion of ADAR1 from smooth muscle cells (SMCs)—key cells of blood vessel walls—has also been shown to reduce AAA formation in mice. Now Cai and colleagues show that SMCs are not the only cells in which ADAR1 plays a role in AAA. Mice whose macrophages lacked ADAR1, were more resistant to AAA induction than were their wildtype counterparts. And the ADAR1-lacking macrophages were less inflammatory. Mechanistically, the team showed that ADAR1 normally enhances inflammation not by its RNA editing activity but by degrading another RNA protein called Drosha, which triggers a molecular cascade to inflammatory signaling. Finally, the team showed this ADAR1-Drosha interaction also exists in human AAA tissue, thus confirming the clinical relevance of their discoveries.Circulating Extracellular Vesicle-Propagated microRNA Signature a A Vascular Calcification Factor in Chronic Kidney Disease (p 415)Download figureDownload PowerPointExtracellular vesicles drive vascular calcification in chronic kidney disease, say Koide et al.Declining renal function in chronic kidney disease (CKD) is associated with the risk of cardiovascular issues such as vascular calcification. This link to calcification is partly due to the body’s altered handling of minerals. But, as Koide and colleagues show, extracellular vesicles (EVs), also play a role. EVs are membrane-bound packets released from cells that act as an inter-cellular and inter-organ communication system. Previously, the serum of CKD patients, but not healthy subjects, was shown to promote calcification of cultured vascular smooth muscle cells (VSMCs), but the agent responsible was unknown. Now the team show, serum from rats with CKD also promotes VSMC calcification, but not if EVs are depleted. Furthermore, injection of an EV inhibitor into CKD-model mice prevented vascular calcification. Analyses of EVs from CKD rodents revealed four microRNAs that were less abundant than in control EVs. And these miRNAs were found to target and suppress the pro-calcification activity of growth factor VEGFA. The same four miRNAs were reduced in human CKD patient EVs where levels of the RNAs correlated with kidney function. The authors thus conclude, these EV RNAs have the potential to be biomarkers of disease severity as well as targets for new therapies. Previous Back to top Next FiguresReferencesRelatedDetailsRelated articlesADAR1 Non-Editing Function in Macrophage Activation and Abdominal Aortic AneurysmDunpeng Cai, et al. Circulation Research. 2023;132:e78-e93Circulating Extracellular Vesicle-Propagated microRNA Signature as a Vascular Calcification Factor in Chronic Kidney DiseaseTakaaki Koide, et al. Circulation Research. 2023;132:415-431CNP Promotes Antiarrhythmic Effects via Phosphodiesterase 2Eleder Cachorro, et al. Circulation Research. 2023;132:400-414 February 17, 2023Vol 132, Issue 4 Advertisement Article InformationMetrics © 2023 American Heart Association, Inc.https://doi.org/10.1161/RES.0000000000000595 Originally publishedFebruary 16, 2023 PDF download Advertisement

Calcium isotopes as a biomarker for vascular calcification in chronic kidney disease.

Calcium balance is abnormal in adults with chronic kidney disease (CKD) and is associated with the development of vascular calcification. It is currently not routine to screen for vascular calcification in CKD patients. In this cross-sectional study, we investigate whether the ratio of naturally occurring calcium (Ca) isotopes, 44Ca and 42Ca, in serum could be used as a noninvasive marker of vascular calcification in CKD. We recruited 78 participants from a tertiary hospital renal center: 28 controls, 9 subjects with mild-moderate CKD, 22 undertaking dialysis and 19 who received a kidney transplant. For each participant, systolic blood pressure, ankle brachial index, pulse wave velocity, and estimated glomerular filtration rate were measured, along with serum markers. Calcium concentrations and isotope ratios were measured in urine and serum. While we found no significant association between urine Ca isotope composition (noted δ44/42Ca) between the different groups, δ44/42Ca values in serum were significantly different between healthy controls, subjects with mild-moderate CKD and those undertaking dialysis (P<0.01). Receiver operative characteristic curve analysis shows that the diagnostic utility of serum δ44/42Ca for detecting medial artery calcification is very good (AUC=0.818, sensitivity 81.8% and specificity 77.3%, P<0.01), and performs better than existing biomarkers. Although our results will need to be verified in prospective studies across different institutions, serum δ44/42Ca has the potential to be used as an early screening test for vascular calcification.

Calciprotein Particles Induce Endothelial Dysfunction by Impairing Endothelial Nitric Oxide Metabolism.

Calciprotein particles (CPPs) are associated with the development of vascular calcifications in chronic kidney disease. The role of endothelial cells (ECs) in this process is unknown. Here, we investigated the interaction of CPPs and ECs, thereby focusing on endothelial nitric oxide metabolism and oxidative stress. CPPs were generated in calcium- and phosphate-enriched medium. Human umbilical vein endothelial cells were exposed to different concentrations of CPPs (0-100 µg/mL) for 24 or 72 hours. Ex vivo porcine coronary artery rings were used to measure endothelial cell-dependent vascular smooth muscle cell relaxation after CPP exposure. Serum samples from an early chronic kidney disease cohort (n=245) were analyzed for calcification propensity (measure for CPP formation) and nitrate and nitrite levels (NOx). CPP exposure for 24 hours reduced eNOS (endothelial nitric oxide synthase) mRNA expression and decreased nitrite production, indicating reduced nitric oxide bioavailability. Also, 24-hour CPP exposure caused increased mitochondria-derived superoxide generation, together with nitrotyrosine protein residue formation. Long-term (72 hours) exposure of human umbilical vein endothelial cells to CPPs induced eNOS uncoupling and decreased eNOS protein expression, indicating further impairment of the nitric oxide pathway. The ex vivo porcine coronary artery model showed a significant reduction in endothelial-dependent vascular smooth muscle cell relaxation after CPP exposure. A negative association was observed between NOx levels and calcification propensity (r=-0.136; P=0.049) in sera of (early) chronic kidney disease patients. CPPs cause endothelial cell dysfunction by impairing nitric oxide metabolism and generating oxidative stress. Our findings provide new evidence for direct effects of CPPs on ECs and pathways involved.