Novel long noncoding lncARF mediated hyperhomocysteinemia-induced atherosclerosis via autophagy inhibition in foam
Ning Ding1, Shengchao Ma1, Qingning Chang2
1NHC Key Laboratory of Metabolic Cardiovascular Diseases Research, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Ningxia Medical University, Yinchuan 750004, China; School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China.
Insights
This study identifies lncARF as a key player in homocysteine-induced atherosclerosis. Knocking down lncARF promotes autophagy and reduces atherosclerotic lesions, offering potential new diagnostic and therapeutic targets.
Area of Science:
- Molecular Biology
- Cardiovascular Research
- Epigenetics
Background:
- Homocysteine (Hcy) is a known risk factor for atherosclerosis.
- Long non-coding RNAs (lncRNAs) are implicated in atherosclerosis, but mechanisms remain unclear.
Purpose of the Study:
- To investigate the role of lncARF in Hcy-induced atherosclerosis.
- To elucidate the underlying mechanisms of lncARF's involvement.
Main Methods:
- RNA sequencing identified lncARF in Hcy-treated foam cells.
- lncARF knockdown (in vivo/in vitro) assessed its function.
- Mass spectrometry, RNA pull-down, and RIP assays explored mechanisms.
- ChIP and Mass array assays analyzed transcriptional activation.
- ROC curve analysis evaluated diagnostic value.
Main Results:
- lncARF was upregulated in atherosclerotic plaques.
- lncARF knockdown promoted autophagy and reduced lesions.
- lncARF binds RRAGD, activating PI3K/Akt and MAPK pathways.
- FosB and DNA hypomethylation mediated lncARF transcriptional activation.
- lncARF levels correlated with Hcy and distinguished HHcy patients.
Conclusions:
- lncARF protects against atherosclerosis via epigenetic modifications and RRAGD signaling.
- lncARF may serve as a diagnostic biomarker for atherosclerosis.
- lncARF presents a potential therapeutic target for atherosclerosis treatment.
Introduction:
Homocysteine (Hcy) is well recognized to be an independent risk factor for atherosclerosis. Long non-coding RNAs (lncRNAs) are emerging regulators of pathophysiological processes including atherosclerosis, while the underlying mechanisms of its involvement in Hcy induced-atherosclerosis remain largely unknown.
Objectives:
The primary aim of this study is to assess the role of lncARF (autophagy-related factor induced by Hcy) in Hcy induced-atherosclerosis and related mechanism.
Methods:
RNA sequencing of foam cells treated with Hcy revealed a novel specific long noncoding RNA called lncARF. Locked nucleic acid gapmeRs-mediated lncARF knockdown was used to explore the role of lncARF both in vivo and in vitro. Mass spectrometry, RNA pull-down and RNA immunoprecipitation (RIP) assays were employed to uncover a mechanistic role of lncARF. Mass array assay and chromatin immunoprecipitation (ChIP) were used to detect the transcriptional activation of lncARF mediated by transcription factor. Clinically, receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value of lncARF in atherosclerotic patients with hyperhomocysteinemia (HHcy).
Results:
We observed that the expression of lncARF was substantially upregulated in atherosclerotic plaques, and knockdown of lncARF decreased the formation of atherosclerotic lesions by promoting autophagy in foam cells. Mechanistically, lncARF physically binds to RRAGD and inhibits its ubiquitination, further activating the PI3K/Akt and MAPK signaling pathways. Moreover, in vitro experiments showed that transcription factor FosB inhibited the binding of DNMT1 at the lncARF promoter, leading to transcriptional activation through DNA hypomethylation. Clinically, lncARF expression was positively correlated with serum Hcy levels, and it could distinguish atherosclerotic patients with HHcy with a high area under the ROC curve, sensitivity and specificity.
Conclusions:
Our study highlights the mechanisms of lncARF in protecting against the development of atherosclerosis involving the epigenetic modifications and RRAGD/PI3K/Akt and RRAGD/MAPK signaling pathways, which may provide novel diagnostic biomarkers to improve atherosclerosis treatment.
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