RNF213 variant and autophagic impairment: A pivotal link to endothelial dysfunction in moyamoya disease
Hee Sun Shin1, Geun Hwa Park2, Eun Sil Choi1
1Department of Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, Korea.
Abstract:
Moyamoya disease (MMD) is closely associated with the Ring Finger Protein 213 (RNF213), a susceptibility gene for MMD. However, its biological function remains unclear. We aimed to elucidate the role of RNF213 in the damage incurred by human endothelial cells under oxygen-glucose deprivation (OGD). We analyzed autophagy in peripheral blood mononuclear cells (PBMCs) derived from patients carrying either RNF213 wildtype (WT) or variant (p.R4810K). Subsequently, human umbilical vein endothelial cells (HUVECs) were transfected with RNF213 WT (HUVECWT) or p.R4810K (HUVECR4810K) and exposed to OGD for 2 h. Immunoblotting was used to analyze autophagy marker proteins, and endothelial function was analyzed by tube formation assay. Autophagic vesicles were observed using transmission electron microscopy. Post-OGD exposure, we administered rapamycin and cilostazol as potential autophagy inducers. The RNF213 variant group during post-OGD exposure (vs. pre-OGD) showed autophagy inhibition, increased protein expression of SQSTM1/p62 (p < 0.0001) and LC3-II (p = 0.0039), and impaired endothelial function (p = 0.0252). HUVECR4810K during post-OGD exposure (versus pre-OGD) showed a remarkable increase in autophagic vesicles. Administration of rapamycin and cilostazol notably restored the function of HUVECR4810K and autophagy. Our findings support the pivotal role of autophagy impaired by the RNF213 variant in MMD-induced endothelial cell dysfunction.
Insights
The Ring Finger Protein 213 (RNF213) variant impairs autophagy, leading to endothelial cell dysfunction in Moyamoya disease (MMD). Treatments like rapamycin restored cell function and autophagy.
Area of Science:
- Vascular Biology
- Cellular Mechanisms
- Genetics
Background:
- Moyamoya disease (MMD) is linked to the RNF213 gene, but its function in endothelial cells is unclear.
- Understanding RNF213's role is crucial for MMD pathogenesis.
- Autophagy dysregulation is implicated in various cellular stresses.
Purpose of the Study:
- To investigate the role of RNF213 variants in human endothelial cell damage under oxygen-glucose deprivation (OGD).
- To analyze the impact of RNF213 on autophagy and endothelial function.
- To evaluate potential therapeutic interventions for RNF213-associated endothelial dysfunction.
Main Methods:
- Analyzed autophagy in patient-derived cells and RNF213-transfected endothelial cells (HUVECs).
- Exposed cells to OGD and assessed autophagy markers (SQSTM1/p62, LC3-II) via immunoblotting.
- Evaluated endothelial function using tube formation assays and transmission electron microscopy.
Main Results:
- The RNF213 variant impaired autophagy, increased SQSTM1/p62 and LC3-II levels, and reduced endothelial function post-OGD.
- RNF213-transfected HUVECs showed increased autophagic vesicles after OGD.
- Rapamycin and cilostazol treatment restored HUVEC function and autophagy.
Conclusions:
- RNF213 variants play a critical role in MMD by impairing endothelial cell autophagy.
- Autophagy dysfunction is a key mechanism in RNF213-associated endothelial cell damage.
- Pharmacological induction of autophagy may offer therapeutic potential for MMD.
