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

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Tianlei Chen ◽  
Huijuan Mao ◽  
Cheng Chen ◽  
Lin Wu ◽  
Ningning Wang ◽  
...  

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.

Author(s):  
Yun Zhou ◽  
Li-Long Wei ◽  
Rui-Ping Zhang ◽  
Cheng-Wu Han ◽  
Yongtong Cao

AbstractLipid metabolism is closely related to the improvement of vascular calcification (VC) in chronic kidney disease (CKD). Globular adiponectin (gAd) has been reported to be involved in the development of VC in CKD, but the detailed regulatory role remains unclear. The present study is aimed to investigate the biological function and the underlying regulation mechanism of gAd in the process of VC during CKD. Vascular smooth muscle cells (VSMCs) calcification was determined by Alizarin Red S staining. Protein signaling related with VC was tested by western blotting. The expression and intracellular localization of runt-related transcription factor 2 (Runx2) was detected by immunofluorescence and uraemic rat with VC was established by a two-step nephrectomy. Combined with the results of Alizarin Red S staining, we discovered that β-glycerophosphate (β-Gp)-induced the osteoblastic differentiation of VSMCs was significantly reversed by gAd treatment. Along with the VSMCs calcification and the increase of Runx2 in β-Gp-exposed VSMCs, the activities of protein kinase B (AKT) and Wnt/β-catenin pathway were enhanced, but that were counteracted by the exposure of gAd in rat and human VSMCs. After administration with agonists of the Wnt (SKL2001) and AKT (SC79), there appeared more osteoblastic differentiation and higher expression of Runx2 in gAd-treated VSMCs, but showing lower impact in the presence of SC79 than that in the presence of SKL2001. In the in vivo experiments, intravenous injection of gAd also significantly inhibited VC and Runx2 level in uraemic rat in a dose-dependent manner, possibly through regulating Wnt/β-catenin pathway. This study demonstrates that gAd ameliorates osteoblastic differentiation of VSMCs possibly by blocking PI3K/AKT and Wnt/β-catenin signaling transduction. The findings provide an important foundation for gAd in treating VC in kidney diseases.


2021 ◽  
Author(s):  
Li Chen ◽  
Rongrong Zhang ◽  
Jinyin Li ◽  
Yiping Gao ◽  
Shilong Mao

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.


1994 ◽  
Vol 269 (11) ◽  
pp. 8504-8509
Author(s):  
K.A. Pritchard ◽  
M.K. O'Banion ◽  
J.M. Miano ◽  
N. Vlasic ◽  
U.G. Bhatia ◽  
...  

2005 ◽  
Vol 108 (6) ◽  
pp. 523-530 ◽  
Author(s):  
Giovanna CASTOLDI ◽  
Serena REDAELLI ◽  
Willy M. M. van de GREEF ◽  
Cira R. T. di GIOIA ◽  
Giuseppe BUSCA ◽  
...  

Ang II (angiotensin II) has multiple effects on vascular smooth muscle cells through the modulation of different classes of genes. Using the mRNA differential-display method to investigate gene expression in rat aortic smooth muscle cells in culture in response to 3 h of Ang II stimulation, we observed that Ang II down-regulated the expression of a member of the family of transmembrane receptors for Wnt proteins that was identified as Fzd2 [Fzd (frizzled)-2 receptor]. Fzds are a class of highly conserved genes playing a fundamental role in the developmental processes. In vitro, time course experiments demonstrated that Ang II induced a significant increase (P<0.05) in Fzd2 expression after 30 min, whereas it caused a significant decrease (P<0.05) in Fzd2 expression at 3 h. A similar rapid up-regulation after Ang II stimulation for 30 min was evident for TGFβ1 (transforming growth factor β1; P<0.05). To investigate whether Ang II also modulated Fzd2 expression in vivo, exogenous Ang II was administered to Sprague–Dawley rats (200 ng·kg−1 of body weight·min−1; subcutaneously) for 1 and 4 weeks. Control rats received normal saline. After treatment, systolic blood pressure was significantly higher (P<0.01), whereas plasma renin activity was suppressed (P<0.01) in Ang II- compared with the saline-treated rats. Ang II administration for 1 week did not modify Fzd2 expression in aorta of Ang II-treated rats, whereas Ang II administration for 4 weeks increased Fzd2 mRNA expression (P<0.05) in the tunica media of the aorta, resulting in a positive immunostaining for fibronectin at this time point. In conclusion, our data demonstrate that Ang II modulates Fzd2 expression in aortic smooth muscle cells both in vitro and in vivo.


Sign in / Sign up

Export Citation Format

Share Document