The Bioactive Substance Secreted by MSC Retards Mouse Aortic Vascular Smooth Muscle Cells Calcification

Background. Vascular calcification, which is associated with low-level chronic inflammation, is a complication that occurs during aging, atherosclerosis, chronic kidney disease, diabetes mellitus, and hyperlipaemia. In this study, we used conditioned media from mesenchymal stem cells (MSC-CM), a source of autologous cytokines, to test the hypothesis that MSC-CM inhibits vascular smooth muscle cell (VSMC) calcification by suppressing inflammation and apoptosis. Methods. VSMCs were treated with β-glycerophosphate (β-GP) to induce calcification and MSC-CM was used as a treatment. Calcium deposition was evaluated using alizarin red and von Kossa staining after a 7-day induction period. Intracellular calcium contents were measured via the o-cresolphthalein complexone method, and alkaline phosphatase (ALP) activity was determined using the para-nitrophenyl phosphate method. The expressions of specific-osteogenic markers, inflammatory cytokines, and apoptosis-associated genes/proteins were examined by real-time polymerase chain reaction or western blotting. Results. MSC-CM inhibited β-GP-induced calcium deposition in VSMCs and decreased intracellular calcium content and ALP activity. Additionally, MSC-CM suppressed the β-GP-induced increases in BMP2, Msx2, Runx2, and osteocalcin expression. Additionally, MSC-CM decreased the expression of TNF-α, IL-1β, and IL-6 in VSMC. MSC-CM also partly blocked β-GP-induced VSMC apoptosis, which was associated with an increase in the Bcl-2/Bax expression ratio and a decrease in caspase-3 expression. Conclusion. Our study results suggest that MSC-CM can inhibit VSMC calcification. This suggests a potential novel clinical application for MSCs in the treatment of vascular calcification and associated diseases.

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MO441CALPROTECTIN IS A NOVEL CONTRIBUTING FACTOR IN VASCULAR CALCIFICATION AND A PREDICTOR OF CARDIOVASCULAR OUTCOME IN CKD PATIENTS*

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfab090.003 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

Ana Amaya Garrido ◽

José M Valdivielso ◽

Stanislas Faguer ◽

Arnaud Del Bello ◽

Benedicte Buffin-Meyer ◽

...

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Calcification ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Calcium Deposition ◽

Alizarin Red ◽

Serum Proteome ◽

Ckd Stage

Abstract Background and Aims Vascular calcification, leading to aortic stiffening and heart failure, is decisive risk factor for cardiovascular (CV) mortality in patients with chronic kidney disease (CKD). Promoted by bone mineral disorder and systemic inflammation in CKD patients, vascular calcification is a complex mechanism involving osteochondrogenic differentiation of vascular smooth muscle cells (VSMCs) and abnormal deposition of minerals in the vascular wall. Despite intensive research efforts in recent years, available treatments have limited effect and none of them prevent or reverse vascular calcification. The aim of this study was to analyse the serum proteome of CKD stage 3-4 patients in order to unravel new molecular changes associated to CV morbid-mortality and to decipher the role of novel candidates on vascular calcification to provide potential new therapeutic agents. Method In this study we used serum samples from two independent cohorts: 112 CKD stage 3-4 patients with a 4 years follow-up for CV events and 222 CKD stage 5 patients exhibiting a broad range of calcification degree determined by histological quantification in the epigastric and/or iliac artery. Serum proteome analysis was performed using tandem mass-spectrometry in a subcohort of 66 CKD3-4 patients and validation of protein candidates was performed using ELISA in the two full cohorts. Human primary vascular smooth muscle cells and mouse aortic rings were used for calcification assays. Calcium content was quantified using QuantiChrom calcium assay kit and calcium deposition was visualized by Alizarin Red and Von Kossa staining. Results Among 443 proteins detected in the serum of CKD3-4 patients, 134 displayed significant modified abundance in patients with CV events (n=32) compared to patients without (n=34). One of the most prominent changes was increased level of calprotectin (up to 8.6 fold, P<.0001). Using ELISA, we validated that higher serum calprotectin levels were strongly associated with higher probability of developing CV complications and increased mortality in CKD stage 3-4 patients (Figure A). Moreover, we showed that higher serum calprotectin was associated with increased vascular calcification levels in CKD stage 5 patients (Figure B). In vitro, calprotectin promoted calcification of human VSMCs (p<0.0001) (Figures C-D) and in mouse aortic rings (p<0.0001) (Figure E-F). Interestingly, these effects were significantly attenuated by paquinimod, a calprotectin inhibitor (Figures C-F). Conclusion Circulating calprotectin is a novel predictor of CV outcome and mortality in CKD patients. Calprotectin also shows calcification-inducing properties and its blockade by paquinimod alleviates its effects. Future experiments will consist in deciphering the signalling pathways involved in the regulation of calcification by calprotectin and evaluating in vivo the therapeutic potential of paquinimod on the development of medial vascular calcification lesions associated with CKD.

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Trimethylamine-N-Oxide Promotes Vascular Calcification Through Activation of NLRP3 (Nucleotide-Binding Domain, Leucine-Rich-Containing Family, Pyrin Domain-Containing-3) Inflammasome and NF-κB (Nuclear Factor κB) Signals

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvbaha.119.313414 ◽

2020 ◽

Vol 40 (3) ◽

pp. 751-765 ◽

Cited By ~ 10

Author(s):

Xiuli Zhang ◽

Yining Li ◽

Pingzhen Yang ◽

Xiaoyu Liu ◽

Lihe Lu ◽

...

Keyword(s):

Chronic Kidney Disease ◽

Smooth Muscle ◽

Kidney Disease ◽

Vascular Smooth Muscle ◽

Vascular Calcification ◽

Ex Vivo ◽

Calcium Content ◽

Nuclear Factor Κb ◽

Alizarin Red ◽

Pyrin Domain

Objectives: Vascular calcification is highly prevalent in patients with chronic kidney disease. Increased plasma trimethylamine N-oxide (TMAO), a gut microbiota-dependent product, concentrations are found in patients undergoing hemodialysis. However, a clear mechanistic link between TMAO and vascular calcification is not yet established. In this study, we investigate whether TMAO participates in the progression of vascular calcification using in vitro, ex vivo, and in vivo models. Approach and Results: Alizarin red staining revealed that TMAO promoted calcium/phosphate-induced calcification of rat and human vascular smooth muscle cells in a dose-dependent manner, and this was confirmed by calcium content assay. Similarly, TMAO upregulated the expression of bone-related molecules including Runx2 (Runt-related transcription factor 2) and BMP2 (bone morphogenetic protein-2), suggesting that TMAO promoted osteogenic differentiation of vascular smooth muscle cells. In addition, ex vivo study also showed the positive regulatory effect of TMAO on vascular calcification. Furthermore, we found that TMAO accelerated vascular calcification in rats with chronic kidney disease, as indicated by Mico-computed tomography analysis, alizarin red staining and calcium content assay. By contrast, reducing TMAO levels by antibiotics attenuated vascular calcification in chronic kidney disease rats. Interestingly, TMAO activated NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome and NF-κB (nuclear factor κB) signals during vascular calcification. Inhibition of NLRP3 inflammasome and NF-κB signals attenuated TMAO-induced vascular smooth muscle cell calcification. Conclusions: This study for the first time demonstrates that TMAO promotes vascular calcification through activation of NLRP3 inflammasome and NF-κB signals, suggesting the potential link between gut microbial metabolism and vascular calcification. Reducing the levels of TMAO could become a potential treatment strategy for vascular calcification in chronic kidney disease.

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The Role and Mechanism ofα-Klotho in the Calcification of Rat Aortic Vascular Smooth Muscle Cells

BioMed Research International ◽

10.1155/2015/194362 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 14

Author(s):

Tianlei Chen ◽

Huijuan Mao ◽

Cheng Chen ◽

Lin Wu ◽

Ningning Wang ◽

...

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Signaling Pathway ◽

Vascular Smooth Muscle Cells ◽

Calcium Content ◽

Alizarin Red S ◽

Alizarin Red ◽

Calcium Deposits

Objective. To investigate the role and possible mechanism ofα-Klotho in the calcification and the osteogenic transition of cultured VSMCs.Methods. VSMCs were culturedin vitroand divided into 5 groups, each using a different medium: (1) control; (2)β-GP; (3)β-GP + Klotho; (4)β-GP + LiCl; (5)β-GP + Klotho + LiCl. Calcium deposits were visualized using Alizarin Red S staining. The calcium concentrations were determined by the o-cresolphthalein complexone method. BMP2, Runx2 andβ-catenin levels were estimated by western blotting, and the level ofα-SMA was determined by using immunofluorescence at day 12.Results.β-GP induced an increase in the expression of BMP2, Runx2, andβ-catenin. The calcium content increased, and the expression ofα-SMA decreased. Alizarin Red S staining was positive under the high phosphorus conditions. BMP2, Runx2, andβ-catenin levels and the calcium content decreased when the cells were cultured with rmKlotho; however, the levels of each were upregulated after treatment with the LiCl.Conclusions. Klotho can ameliorate the calcification and osteogenic transition of VSMCs induced byβ-GP. The mechanism of Klotho in preventing calcification in VSMCs may be partially mediated by the inhibition of the Wnt/β-catenin signaling pathway.

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Abstract 319: Intermedin Attenuates Vascular Calcification by Upregulating Klotho via CRLR/RAMP3 Receptor Complex and cAMP/PKA Signaling Pathway in Rats With Chronic Kidney Disease

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.319 ◽

2014 ◽

Vol 34 (suppl_1) ◽

Author(s):

Jin-Rui Chang ◽

Yue-Long Hou ◽

Wei-Wei Lu ◽

Jin-Sheng Zhang ◽

Yan-Rong Yu ◽

...

Keyword(s):

Chronic Kidney Disease ◽

Smooth Muscle ◽

Kidney Disease ◽

Signaling Pathway ◽

Vascular Calcification ◽

Small Interfering Rna ◽

Calcium Deposition ◽

Alp Activity ◽

Klotho Protein ◽

Interfering Rna

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.

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Fibulin-3 Attenuates Phosphate-Induced Vascular Smooth Muscle Cell Calcification by Inhibition of Oxidative Stress

Cellular Physiology and Biochemistry ◽

10.1159/000489144 ◽

2018 ◽

Vol 46 (4) ◽

pp. 1305-1316 ◽

Cited By ~ 19

Author(s):

Trang T. D. Luong ◽

Nadeshda Schelski ◽

Beate Boehme ◽

Manousos Makridakis ◽

Antonia Vlahou ◽

...

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Mrna Expression ◽

Vascular Calcification ◽

Muscle Cells ◽

Additional Treatment ◽

Calcium Deposition

Background/Aims: Fibulin-3, an extracellular matrix glycoprotein, inhibits vascular oxidative stress and remodeling in hypertension. Oxidative stress is prevalent in chronic kidney disease (CKD) patients and is an important mediator of osteo-/chondrogenic transdifferentiation and calcification of vascular smooth muscle cells (VSMCs) during hyperphosphatemia. Therefore, the present study explored the effects of Fibulin-3 on phosphate-induced vascular calcification. Methods: Experiments were performed in primary human aortic smooth muscle cells (HAoSMCs) treated with control or with phosphate without or with additional treatment with recombinant human Fibulin-3 protein or with hydrogen peroxide as an exogenous source of oxidative stress. Results: Treatment with calcification medium significantly increased calcium deposition in HAoSMCs, an effect significantly blunted by additional treatment with Fibulin-3. Moreover, phosphate-induced alkaline phosphatase activity and mRNA expression of osteogenic and chondrogenic markers MSX2, CBFA1, SOX9 and ALPL were all significantly reduced by addition of Fibulin-3. These effects were paralleled by similar regulation of oxidative stress in HAoSMCs. Phosphate treatment significantly up-regulated mRNA expression of the oxidative stress markers NOX4 and CYBA, down-regulated total antioxidant capacity and increased the expression of downstream effectors of oxidative stress PAI-1, MMP2 and MMP9 as well as BAX/BLC2 ratio in HAoSMCs, all effects blocked by additional treatment with Fibulin-3. Furthermore, the protective effects of Fibulin-3 on phosphate-induced osteogenic and chondrogenic markers expression in HAoSMCs were reversed by additional treatment with hydrogen peroxide. Conclusions: Fibulin-3 attenuates phosphate-induced osteo-/ chondrogenic transdifferentiation and calcification of VSMCs, effects involving inhibition of oxidative stress. Up-regulation or supplementation of Fibulin-3 may be beneficial in reducing the progression of vascular calcification during hyperphosphatemic conditions such as CKD.

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Exosomal miR-151-3p Induces Calcium Deposition in Vascular Smooth Muscle Cells by Inhibiting Atg5

10.21203/rs.3.rs-172981/v1 ◽

2021 ◽

Author(s):

Li Chen ◽

Rongrong Zhang ◽

Jinyin Li ◽

Yiping Gao ◽

Shilong Mao

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Calcium Deposition ◽

Alizarin Red ◽

Potential Biomarker

Abstract Background: Calcium deposition in vascular smooth muscle cells (VSMCs) can lead to the rigidity of the vasculature and an increase of risk in cardiac events. This study aimed to explore the role of exosomal microRNA-151-3p (miR-151-3p) in the regulation of VSMC calcification. Methods: A cellular calcification model was established using the mouse primary aortic VSMCs by β-glycerophosphate treatment. The calcium deposition was evaluated by Alizarin Red staining. The expression of miR-151-3p in exosomes was evaluated by qRT-PCR. The relationship between miR-151-3p and Atg5 was determined by bioinformatics analysis and dual-luciferase gene reporter assay. The exosome derived from mouse VSMCs transfected with miR-151-3p mimics/inhibitor were isolated and used to stimulate VSMCs. The expression of Atg5, α-SMA, OPN, Runx2 and BMP2 was evaluated by western blot. An animal model was established to investigate the role of miR-151-3p in exosomes.Results: MiR-151-3p was significantly upregulated in the exosomes of VSMCs treated with β-glycerophosphate. Exosomes derived from calcific VSMCs increased the calcium deposition of general VSMCs without any treatment. Exosomes derived from miR-151-3p mimics transfected VSMCs increased the expression of Runx2 and BMP2, while reduced the expression of α-SMA and OPN in general VSMCs. and exosomes derived from miR-151-3p inhibitor transfected VSMCs reversed these effects in vitro. Meanwhile, miR-151-3p served as a ceRNA of Atg5 by directly binding to the 3'UTR of Atg5. Moreover, the expression of α-SMA, OPN, Runx2 and BMP2 in vivo was consistent with the results in VSMCs in vitro.Conclusion: Our study revealed that miR-151-3p in VSMCs-derived exosomes might induce calcium deposition through regulating Atg5 expression, suggesting that miR-151-3p might be a potential biomarker for vascular calcification.

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Melatonin attenuates vascular calcification by activating mitochondrial fusion and mitophagy via an AMPK/OPA1 signaling pathway

10.21203/rs.2.17699/v1 ◽

2019 ◽

Author(s):

chenweiren chen ◽

jia qi yang ◽

fang liu ◽

xue qin shen ◽

yuan sha

Keyword(s):

Vascular Calcification ◽

Mitochondrial Fusion ◽

Calcium Deposition ◽

Protective Effects ◽

Melatonin Treatment ◽

Western Blots ◽

Alizarin Red ◽

Mitofusin 2 ◽

Alp Activity ◽

Compound C

Abstract Background: Mitochondrial fusion/mitophagy play a role in cardiovascular calcification. Melatonin has been shown to protect against cardiovascular disease. This study sought to explore whether melatonin attenuates vascular calcification by regulating mitochondrial fusion/mitophagy via an AMP activated protein kinase/ Optic atrophy 1 (AMPK/OPA1) signaling pathway.Methods: The effects of melatonin on vascular calcification were investigated in vascular smooth muscle cells (VSMCs). Calcium deposits were visualised by Alizarin red staining. Calcium content and alkaline phosphatase (ALP) activity were used to evaluate osteogenic differentiation. Western blots were used to measure expression of runt-related transcription factor 2 (Runx2), mitofusin 2 (Mfn2), mito-light chain 3 II (LC3II) and cleaved caspase3. Results: Melatonin markedly reduced calcium deposition and ALP activity. Runx2 and cleaved caspase3 were found to be down-regulated and Mfn2 or mito-LC3II was found to be enhanced in response to melatonin, together with a decrease in mitochondrial superoxide levels. Melatonin also maintained mitochondrial function and promoted mitochondrial fusion/mitophagy via OPA1 pathway. But OPA1 deletion abolished the protective effects of melatonin on VSMC calcification. Melatonin treatment significantly increased the p-AMPK and OPA1 protein expression. Treatment with compound C ablated the benefit observed with melatonin treatment. Conclusions: Melatonin protects VSMC against calcification by promoting mitochondrial fusion/mitophagy via AMPK/OPA1 pathway.

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Uremic Patients with Increased Vascular Calcification Score Have Serum with High Calcific Potential: Role of Vascular Smooth Muscle Cell Osteoblastic Differentiation and Apoptosis

Blood Purification ◽

10.1159/000497229 ◽

2019 ◽

Vol 48 (2) ◽

pp. 142-149 ◽

Cited By ~ 5

Author(s):

Paola Ciceri ◽

Andrea Galassi ◽

Carlo Alfieri ◽

Piergiorgio Messa ◽

Mario Cozzolino

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Vascular Calcification ◽

Osteoblastic Differentiation ◽

Calcium Deposition ◽

Calcification Score ◽

Uremic Serum ◽

Uremic Patients ◽

Apoptosis And Necrosis

Background/Aims: Uremic patients experience premature vascular ageing that causes cardiovascular morbidity. In this study, we investigated the relationship between uremic serum calcific potential induced by high phosphate (Pi) and vascular calcification score (VCS). Methods: Vascular smooth muscle cells (VSMCs) were cultured with 3.5 mM Na3PO4 (Pi) with 10% uremic serum and calcium deposition, markers of osteoblastic transformation, and apoptosis were evaluated. Results: Culture with uremic serum and high-Pi significantly induced calcification (0.21 ± 0.03 vs. 8.05 ± 0.6; ctr vs. Pi; OD/mg protein; p < 0.01). We next stratified patients with respect of the degree of VCS in 2 groups: absence of vascular calcification (VC) “no VC group” and presence of VC “VC group”. We found that there was a significant correlation between VCS and uremic serum calcific potential induced by high Pi in vitro (p < 0.01). Interestingly, uremic sera of the “VC group” were more effective than sera from the “no VC group”, in downregulating α-actin and SM22α, after treatment with high-Pi (41.3 ± 4.7 vs. 23.3 ± 2.9 and 25.6 ± 6.8 vs. 8.14 ± 2.3; VC vs. no VC group, α-actin and SM22α respectively; Δ intensity area; p < 0.01). Similarly, sera from “VC group” were more effective than sera from “no VC group” in adjuvanting the high-Pi effect of increasing osteoblastic markers, such as bone morphogenic protein 2 (BMP2), osteocalcin (OC), and runt-related transcription factor 2 (RUNX2; 39.1 ± 11.3 vs. 5.0 ± 2.6 BMP2; 12.2 ± 4.2 vs. 1.7 ± 0.3 OC; 2.9 ± 0.4 vs. 1.2 ± 0.2 RUNX2; VC vs. no VC group respectively; p < 0.05). We found a similar pattern with significantly higher apoptosis and necrosis induction by sera from the “VC group” compared to the “no VC group” (2.05 ± 0.33 vs. 1.29 ± 0.13 and 54.1 ± 19.5 vs. 27.4 ± 10.6; Pi; VC group vs. no VC group; enrichment factor of apoptotic or necrotic fragments, respectively; p < 0.05). Conclusions: We conclude that VCS of end-stage renal disease patients significantly correlates with serum-calcific potential induced by high Pi. In addition, uremic patients with higher VCS have sera with a higher potential to induce VSMC osteoblastic trans-differentiation, apoptosis, and necrosis.

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Abstract 12584: Transcription Factor EB Regulates Vascular Smooth Muscle Calcification

Circulation ◽

10.1161/circ.142.suppl_3.12584 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Ryo Ishiwata ◽

Yuji Morimoto

Keyword(s):

Transcription Factor ◽

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Protein Expression ◽

Vascular Calcification ◽

Inorganic Phosphate ◽

Calcium Deposition ◽

Nuclear Fraction ◽

Lysosomal Activity ◽

Transcription Factor Eb

Introduction: Vascular calcification is a strong predictor of cardiovascular-related mortality. Hyperphosphatemia causes phenotypic switches of vascular smooth muscle cells (VSMCs), leading to medial calcification. Recent studies have suggested that dysfunction of the autophagy-lysosomal pathway in VSMCs is a cause of vascular calcification, but the process through which this pathway fails is elusive. Transcription factor EB (TFEB) is a master regulator of lysosome biogenesis; its function in VSMCs is unknown. Hypothesis: We assessed the hypothesis that the dysfunction of TFEB in VSMCs is a cause of vascular calcification. Methods and Results: We induced vascular calcification in wild type mouse aorta with an ex vivo hyperphosphatemia model . Addition of inorganic phosphate at a 1.7 mmol/L for five days decreased TFEB protein expression (0.23 ± 0.10-fold vs. day0, n = 5-7). Immunohistochemistry and alizarin red staining showed that a decrease in TFEB expression in the tunica media was correlated with the formation of calcification. VSMCs were isolated from rat aorta and were cultured for seven days in vitro . Addition of inorganic phosphate dose-dependently decreased TFEB protein expression both in whole cell lysate and in nuclear fraction (0.07± 0.03-fold vs. control, n = 5 ; 0.01 ± 0.003-fold vs. control, n = 4, respectively) while it rather increased mRNA expression of Tfeb (4.48 ± 0.95-fold, n = 7 vs. control). The Decrease in TFEB protein by inorganic phosphate was correlated with the accumulation of TFEB in the SDS-insoluble fraction, suggesting the formation of protein aggregates. The Knockdown of TFEB in VSMCs by siRNA exacerbated phosphate-induced calcium deposition (2.93 ± 0.85-fold, n = 4 vs. negative siRNA). The addition of inorganic phosphate significantly decreased lysosomal activity determined by LysoTracker dye; and treatment with 20 nmol/L of bafilomycin A, a lysosome inhibitor, further accelerated phosphate-induced calcium deposition (13.6 ± 3.69-fold, n = 7 vs. vehicle). Conclusion: In conclusion, TFEB expression in VSMCs is downregulated at the protein level by hyperphosphatemia. The diminution of functional TFEB predisposes to vascular calcification, presumably through downregulating lysosomal activity.

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MO565M2 MACROPHAGES REGULATE MOUSE AORTIC SMOOTH MUSCLE CELL CALCIFICATION BY TRANSMITTING SENESCENCE INFORMATION

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfab086.003 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

Yaping Fang ◽

Xiaodong Zhu ◽

Yu Zhao ◽

Xiao liang Zhang

Keyword(s):

Smooth Muscle ◽

Vascular Calcification ◽

Calcium Content ◽

M2 Macrophage ◽

High Morbidity ◽

M2 Macrophages ◽

Alizarin Red ◽

Aortic Smooth Muscle ◽

Test Kit

Abstract Background and Aims Vascular calcification is highly prevalent in chronic kidney disease (CKD)with high morbidity and mortality. Complex pathological mechanisms are involved in the development of vascular calcification, including aging. Previous work have indicated that M2-macrophage promote mouse aortic smooth muscle cells (MAoSMCs) calcification. The present study aimed to understand the contribution of M2-macrophage to MAoSMCs calcification by focusing on the mechanisms underlying the transmitting senescence information Method The expression of IFITM3 and P16, marker of aging, in aging macrophages were confimed by RT-qPCR, western blotting and immunofluorescence staining. Then, the MAoSMCs were co-cultured with the supernatant of M2 macrophages. The expression of IFITM3 and P16 in MAoSMCs also were detected. Alizarin red staining and calcium content assay were used to analyse MAoSMCs calcification. We modulated the expression of IFITM3 using siRNAs to study M2-macrophages function in regulating MAoSMCs calcification.We detected the expression of IFITM3 and P16 in co-cultivate MAoSMCs and validate intracellular calcium contents by calcium test kit. Results In the present study, we observed a significant increase in the expression of IFITM3 and P16 expression in M2 macrophages.Compared with M0 and M1 macrophages, the expression of IFITM3 and P16 at lowlevel. Alizarin red staining and calcium content assay revealed that M2 macrophage-mediated IFITM3 and P16 overexpression led to an apparent VSMC calcification in the presence of M2 macrophages medium.By contrast, inhibition of IFITM3 by siRNAs significantly blocked calcification of VSMCs in vitro. Moreover, we found that aging macrophages that overexpressed of IFITM3 and P16 increased in rats with CKD. Furthermore, pharmacological inhibition of aging signal was shown to block IFITM3-induced VSMC calcification. These findings demonstrate for the first time that M2 macrophage-mediated IFITM3 contributes to vascular calcification through a mechanism involving transmitting Senescence signalling. Conclusion Collectively, our present study demonstrated that the functional importance of M2 macrophage-IFITM3 dependent vascular calcification and provided a novel mechanistic insight to the macrophage senescence in CKD.

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