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Isolation and Characterization of Primary Rat Valve Interstitial Cells: A New Model to Study Aortic Valve Calcification
Published on: November 20, 2017
Noncoding RNA regulates the expression of Krm1 and Dkk2 to synergistically affect aortic valve lesions
Gaopeng Xian1,2,3, Rong Huang4, Minhui Xu1,2,3
1State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, 510515, Guangzhou, China.
Abstract:
Calcific aortic valve disease (CAVD) is becoming an increasingly important global medical problem, but effective pharmacological treatments are lacking. Noncoding RNAs play a pivotal role in the progression of cardiovascular diseases, but their relationship with CAVD remains unclear. Sequencing data revealed differential expression of many noncoding RNAs in normal and calcified aortic valves, with significant differences in circHIPK3 and miR-182-5p expression. Overexpression of circHIPK3 ameliorated aortic valve lesions in a CAVD mouse model. In vitro experiments demonstrated that circHIPK3 inhibits the osteogenic response of aortic valve interstitial cells. Mechanistically, DEAD-box helicase 5 (DDX5) recruits methyltransferase 3 (METTL3) to promote the N6-methyladenosine (m6A) modification of circHIPK3. Furthermore, m6A-modified circHIPK3 increases the stability of Kremen1 (Krm1) mRNA, and Krm1 is a negative regulator of the Wnt/β-catenin pathway. Additionally, miR-182-5p suppresses the expression of Dickkopf2 (Dkk2), the ligand of Krm1, and attenuates the Krm1-mediated inhibition of Wnt signaling. Activation of the Wnt signaling pathway significantly contributes to the promotion of aortic valve calcification. Our study describes the role of the Krm1-Dkk2 axis in inhibiting Wnt signaling in aortic valves and suggests that noncoding RNAs are upstream regulators of this process.
Insights
Calcific aortic valve disease (CAVD) involves noncoding RNAs like circHIPK3. This study reveals circHIPK3 and miR-182-5p regulate valve calcification by modulating the Wnt/β-catenin pathway, offering potential therapeutic targets.
Area of Science:
- Cardiovascular Biology
- Molecular Medicine
- RNA Biology
Background:
- Calcific aortic valve disease (CAVD) is a growing global health concern with limited pharmacological treatments.
- Noncoding RNAs are implicated in cardiovascular diseases, but their specific role in CAVD is not well understood.
- Understanding the molecular mechanisms underlying CAVD is crucial for developing effective therapies.
Purpose of the Study:
- To investigate the role of noncoding RNAs in the pathogenesis of CAVD.
- To identify specific noncoding RNAs and their targets involved in aortic valve calcification.
- To elucidate the molecular pathways regulated by noncoding RNAs in CAVD.
Main Methods:
- Differential expression analysis of noncoding RNAs in normal versus calcified aortic valves using sequencing data.
- In vivo studies using a CAVD mouse model to assess the effects of circHIPK3.
- In vitro experiments on aortic valve interstitial cells to examine cellular responses and molecular interactions.
- Investigation of the m6A modification of circHIPK3 and its interaction with DDX5 and METTL3.
- Analysis of Kremen1 (Krm1) mRNA stability and its regulation by circHIPK3.
- Assessment of miR-182-5p's effect on Dickkopf2 (Dkk2) and its impact on Wnt/β-catenin signaling.
Main Results:
- Sequencing identified differential expression of circHIPK3 and miR-182-5p in CAVD.
- Overexpression of circHIPK3 reduced aortic valve lesions in a mouse model of CAVD.
- circHIPK3 was found to inhibit the osteogenic differentiation of aortic valve interstitial cells in vitro.
- circHIPK3 is modified by m6A, a process mediated by DDX5 and METTL3, enhancing Krm1 mRNA stability.
- Krm1 acts as a negative regulator of the Wnt/β-catenin pathway, and its inhibition by circHIPK3 promotes calcification.
- miR-182-5p was shown to suppress Dkk2, thereby attenuating Krm1-mediated Wnt signaling inhibition.
- Activation of the Wnt/β-catenin pathway was confirmed to contribute significantly to aortic valve calcification.
Conclusions:
- Noncoding RNAs, specifically circHIPK3 and miR-182-5p, are key upstream regulators in CAVD.
- The Kremen1-Dickkopf2 (Krm1-Dkk2) axis plays a critical role in modulating Wnt/β-catenin signaling in aortic valves.
- Targeting the identified noncoding RNA regulatory network offers a promising therapeutic strategy for CAVD.
