Endothelial damage and vascular calcification in patients with chronic kidney disease

2014 ◽  
Vol 307 (11) ◽  
pp. F1302-F1311 ◽  
Author(s):  
Sagrario Soriano ◽  
Andrés Carmona ◽  
Francisco Triviño ◽  
Mariano Rodriguez ◽  
Marina Alvarez-Benito ◽  
...  

Vascular calcification (VC) is a frequent complication of chronic kidney disease (CKD) and is a predictor of cardiovascular morbidity and mortality. In the present study, we investigated the potential involvement of endothelial microparticles (MPs) and endothelial progenitor cells (EPCs) in the generation of VC in CKD patients. The number of circulating EMPs is greater in patients with VC than without VC (307 ± 167 vs. 99 ± 75 EMPs/μl, P < 0.001). The percentage of EPCs is significantly lower in patient with VC than in patients without VC (0.14 ± 0.11% vs. 0.25 ± 0.18%, P = 0.002). The number of EPCs expressing osteocalcin (OCN) was higher in VC patients (349 ± 63 cells/100,000) than in non-VC patients (139 ± 75 cells/100,000, P < 0.01). In vitro, MPs obtained from CKD patients were able to induce OCN expression in EPCs from healthy donors; the increase in OCN expression was more accentuated if MPs were obtained from CKD patients with VC. MPs from CKD patients also induced OCN expression in vascular smooth muscle cells and fibroblasts. In CKD patients, the rise in endothelial MPs associated with a decrease in the number of EPCs, suggesting an imbalance in the processes of endothelial damage and repair in CKD patients, mainly those with VC. Our results suggest that EPCs, through OCN expression, may directly participate in the process of VC.

2019 ◽  
Vol 35 (5) ◽  
pp. 765-773 ◽  
Author(s):  
Anique D ter Braake ◽  
Coby Eelderink ◽  
Lara W Zeper ◽  
Andreas Pasch ◽  
Stephan J L Bakker ◽  
...  

Abstract Background Phosphate (Pi) toxicity is a strong determinant of vascular calcification development in chronic kidney disease (CKD). Magnesium (Mg2+) may improve cardiovascular risk via vascular calcification. The mechanism by which Mg2+ counteracts vascular calcification remains incompletely described. Here we investigated the effects of Mg2+ on Pi and secondary crystalline calciprotein particles (CPP2)-induced calcification and crystal maturation. Methods Vascular smooth muscle cells (VSMCs) were treated with high Pi or CPP2 and supplemented with Mg2+ to study cellular calcification. The effect of Mg2+ on CPP maturation, morphology and composition was studied by medium absorbance, electron microscopy and energy dispersive spectroscopy. To translate our findings to CKD patients, the effects of Mg2+ on calcification propensity (T50) were measured in sera from CKD patients and healthy controls. Results Mg2+ supplementation prevented Pi-induced calcification in VSMCs. Mg2+ dose-dependently delayed the maturation of primary CPP1 to CPP2 in vitro. Mg2+ did not prevent calcification and associated gene and protein expression when added to already formed CPP2. Confirmatory experiments in human serum demonstrated that the addition of 0.2 mmol/L Mg2+ increased T50 from healthy controls by 51 ± 15 min (P &lt; 0.05) and CKD patients by 44 ± 13 min (P &lt; 0.05). Each further 0.2 mmol/L addition of Mg2+ led to further increases in both groups. Conclusions Our results demonstrate that crystalline CPP2 mediates Pi-induced calcification in VSMCs. In vitro, Mg2+ delays crystalline CPP2 formation and thereby prevents Pi-induced calcification.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Hooi Hooi Ng ◽  
Daniela Medina ◽  
Alexander I Agoulnik ◽  
Joshua Hutcheson

Introduction: Vascular calcification is the most significant predictor of cardiovascular morbidity and mortality, but therapeutic options are unavailable. Relaxin has emerged as a vasoprotective molecule, but several drawbacks prevent therapeutic translation. Targeting the relaxin receptor, RXFP1, is safe and well-tolerated in animal models of vascular disease and humans. We identified a biased allosteric agonist of human RXFP1, ML290, and aimed to test the hypothesis that ML290 arrests the progression of vascular calcification in mouse models of atherosclerosis and chronic kidney disease (CKD). Methods and Results: Recurrent treatment with ML290 significantly prevented ( P = 0.0422, n = 8) and reversed ( P = 0.0489, n = 6) atherosclerotic calcification in humanized ( hRXFP1/hRXFP1 ) Apoe -/- mice fed an atherogenic diet. Longitudinal tracing of mineral formation in the aortic arch of these mice revealed the presence of mineral in vehicle- but not ML290-treated mice after 15 weeks of diet. Accelerated mineral growth was observed in vehicle-treated mice after 20 weeks of the diet, which was reduced by ML290 treatment. In humanized mice with CKD, ML290 significantly prevented ( P = 0.0344, n = 9) medial calcification. In vitro , ML290 reduced ( P = 0.0005, n = 3) superoxide production under osteogenic conditions in vascular smooth muscle cells (VSMCs). Osteogenic changes in VSMC phenotype associate with a release of alkaline phosphatase (ALP) in extracellular vesicles (EVs), which promote mineralization. ML290 treatment significantly ( P = 0.0001, n = 3) suppressed the formation of ALP-loaded EVs in vitro . Bone morphogenetic protein-4, an inducer of osteogenic transitions, and caveolin-1, a scaffolding protein required for calcifying EV formation, were significantly ( P = 0.0059, n = 4) down-regulated after 24 h treatment with ML290 compared to vehicle-treated VSMCs under osteogenic conditions. Conclusions: We demonstrate the therapeutic potential for ML290 to mitigate atherosclerosis and CKD-induced vascular calcification in vivo . The actions of ML290 to prevent medial calcification are in part attributed to its ability to limit the release of calcifying EVs as a result of osteogenic differentiation, and to reduce vascular superoxide production.


2020 ◽  
Author(s):  
Samantha J Borland ◽  
Cecilia Facchi ◽  
Julia Behnsen ◽  
Antony Adamson ◽  
Neil E Humphreys ◽  
...  

AbstractArterial medial calcification is an independent risk factor for mortality in chronic kidney disease. We previously reported that knock-down of PKCα expression increases high phosphate-induced mineral deposition by vascular smooth muscle cells in vitro. This new study tests the hypothesis that PKCα regulates uremia-induced medial calcification in vivo. Female wild-type and PKCα−/− mice underwent a two-stage subtotal nephrectomy and were fed a high phosphate diet for 8 weeks. X-ray micro computed tomography demonstrated that uremia-induced medial calcification was increased in the abdominal aorta and aortic arch of PKCα−/− mice compared to wild-types. Blood urea nitrogen was also increased in PKCα−/− mice compared to wild-types; there was no correlation between blood urea nitrogen and calcification in PKCα−/− mice. Phosphorylated SMAD2 immunostaining was detected in calcified aortic arches from uremic PKCα−/− mice; the osteogenic marker Runx2 was also detected in these areas. No phosphorylated SMAD2 staining were detected in calcified arches from uremic wild-types. PKCα knock-down increased TGF-β1-induced SMAD2 phosphorylation in vascular smooth muscle cells in vitro, whereas the PKCα activator prostratin decreased SMAD2 phosphorylation. In conclusion, loss of PKCα increases uremia-induced medial calcification. The PKCα/TGF-β signaling axis could therefore represent a new therapeutic target for arterial medial calcification in chronic kidney disease.


2016 ◽  
Vol 19 (5) ◽  
pp. 628-642 ◽  
Author(s):  
Rafael Kramann ◽  
Claudia Goettsch ◽  
Janewit Wongboonsin ◽  
Hiroshi Iwata ◽  
Rebekka K. Schneider ◽  
...  

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Jana Holmar ◽  
Heidi Noels ◽  
Joachim Jankowski ◽  
Setareh Orth-Alampour

Abstract Background and Aims Vascular calcification (VC) is one major complication in patients with chronic kidney disease whereas a misbalance in calcium and phosphate metabolism plays a crucial role. The mechanisms underlying VC have not been entirely revealed to date. Therefore are the studies aiming at the identification and characterization of the mediators/uremic toxins involved in VC ongoing and highly relevant. However, currently many different protocols being used in the studies of vascular calcification processes. This complicates the comparison of study outcomes, composing systematic reviews, and meta-analyses. Moreover, the reproducibility of data is hampered, and the efficiency in calcification research through the lack of a standardized protocol is reduced. In this study, we developed a standardized operating protocol for in vitro and ex vivo approaches to aiming at the comparability of these studies. Method We analysed in vitro and ex vivo experimental conditions to study VC. Vascular smooth muscle cells (HAoSMCs) were used for in vitro experiments and aortas from Wistar rats were used for ex vivo experiments. The influence of the following conditions was studied in detail: • Phosphate and calcium concentrations in calcifying media. • Incubation time. • Fetal calf serum (FCS) concentration. The degree of calcification was estimated by quantification of calcium concentrations that were normalized to protein content (in vitro) or to the dry weight of the aortic ring (ex vivo). Additionally, the aortic rings were stained using the von Kossa method. Optimal conditions for investigating medial vascular calcification were detected and summarized in the step-by-step protocol. Results We were able to demonstrate that the degree and the location of VC in vascular smooth muscle cells and aortic rings were highly dependent on the phosphate and CaCl2 concentration in the medium as well as the incubation time. Furthermore, the VC was reduced upon increasing fetal calf serum concentration in the medium. An optimized protocol for studying vascular calcification in vitro and ex vivo was developed and validated. The final protocol (Figure 1) presented will help to standardize in vitro and ex vivo approaches to investigate the processes of vascular calcification. Conclusion In the current study, we developed and validated a standardized operating protocol for systematic in vitro and ex vivo analyses of medial calcification, which is essential for the comparability of the results of future studies.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Jin-Rui Chang ◽  
Yue-Long Hou ◽  
Wei-Wei Lu ◽  
Jin-Sheng Zhang ◽  
Yan-Rong Yu ◽  
...  

Vascular calcification (VC) is highly associated with increased morbidity and mortality in patients with advanced chronic kidney disease(CKD). We previously reported that paracrine/autocrine factor intermedin (IMD) could protect against VC. In the present study we assessed the hypothesis that IMD inhibits VC by upregulating klotho protein. VC in CKD rat was induced by 5/6 nephrectomy plus vitamin D 3 administration and vascular smooth muscle cells (VSMCs) calcification was induced by calcifying media containing β -glycerophosphate and CaCl 2 . IMD (100 ng kg -1 h -1 ) was systemically administered by a mini-osmotic pump. CKD rat aortas showed lower IMD content and increased expression of its receptors (calcitonin receptor-like receptor,CRLR/receptor activity-modifying protein 3, RAMP3), along with increased aortic alkaline phosphatase (ALP) activity and calcium deposition. In vivo administration of IMD significantly reduced aortic ALP activity and calcium deposition in CKD rats when compared with vehicle treatment, which was further confirmed in cultured VSMCs. Concurrently, the loss of smooth muscle lineage markers and klotho protein in aortas was rescued by administering IMD to CKD rats with VC. However, the inhibitory effects of IMD on VC were abolished upon pre-treatment with small interfering RNA to reduce klotho. Moreover, the increased effects of IMD on klotho were abolished upon pretreatment with small interfering RNA to reduce its receptors or with PKA inhibitor H89. These results demonstrated that IMD attenuates VC by upregulating klotho via CRLR/RAMP3-cAMP/PKA signaling pathway in rat with CKD. IMD is an important paracrine/autocrine protective factor for VC.


2019 ◽  
Vol 34 (12) ◽  
pp. 2018-2030 ◽  
Author(s):  
Karim Belmokhtar ◽  
Jeremy Ortillon ◽  
Stéphane Jaisson ◽  
Ziad A Massy ◽  
Camille Boulagnon Rombi ◽  
...  

Abstract Background Chronic kidney disease (CKD) is associated with increased cardiovascular mortality, frequent vascular calcification (VC) and accumulation of uraemic toxins. Advanced glycation end products and S100 proteins interact with the receptor for advanced glycation end products (RAGE). In the present work, we aimed to investigate the role(s) of RAGE in the CKD–VC process. Methods Apoe−/− or Apoe−/−Ager (RAGE)−/− male mice were assigned to CKD or sham-operated groups. A high-phosphate diet was given to a subgroup of Apoe−/−and Apoe−/−Ager−/− CKD mice. Primary cultures of Ager+/+ and Ager−/− vascular smooth muscle cells (VSMCs) were established and stimulated with either vehicle, inorganic phosphate (Pi) or RAGE ligands (S100A12; 20 µM). Results After 12 weeks of CKD we observed a significant increase in RAGE ligand (AGE and S100 proteins) concentrations in the serum of CKD Apoe−/− mice. Ager messenger RNA (mRNA) levels were 4-fold higher in CKD vessels of Apoe−/− mice. CKD Apoe−/− but not CKD Apoe−/− or Ager−/− mice displayed a marked increase in the VC surface area. Similar trends were found in the high-phosphate diet condition. mRNA levels of Runx2 significantly increased in the Apoe−/− CKD group. In vitro, stimulation of Ager+/+VSMCs with Pi or S100A12 induced mineralization and osteoblast transformation, and this was inhibited by phosphonoformic acid (Pi co-transporters inhibitor) and Ager deletion. In vivo and in vitro RAGE was necessary for regulation of the expression of Pit-1, at least in part through production of reactive oxygen species. Conclusion RAGE, through the modulation of Pit-1 expression, is a key molecule in the genesis of VC.


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