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KRAS mutation-induced EndMT of brain arteriovenous malformation is mediated through the TGF-β/BMP-SMAD4 pathway.
- Source :
-
Stroke and vascular neurology [Stroke Vasc Neurol] 2023 Jun; Vol. 8 (3), pp. 197-206. Date of Electronic Publication: 2022 Nov 23. - Publication Year :
- 2023
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Abstract
- Objective: Somatic KRAS mutations have been identified in the majority of brain arteriovenous malformations (bAVMs), and subsequent in vivo experiments have confirmed that KRAS mutation in endothelial cells (ECs) causes AVMs in mouse and zebrafish models. Our previous study demonstrated that the KRAS <superscript>G12D</superscript> mutant independently induced the endothelial-mesenchymal transition (EndMT), which was reversed by treatment with the lipid-lowering drug lovastatin. However, the underlying mechanisms of action were unclear.<br />Methods: We used human umbilical vein ECs (HUVECs) overexpressing the KRAS <superscript>G12D</superscript> mutant for Western blotting, quantitative real-time PCR, and immunofluorescence and wound healing assays to evaluate the EndMT and determine the activation of downstream pathways. Knockdown of SMAD4 by RNA interference was performed to explore the role of SMAD4 in regulating the EndMT. BAVM ECs expressing the KRAS <superscript>G12D</superscript> mutant were obtained to verify the SMAD4 function. Finally, we performed a coimmunoprecipitation assay to probe the mechanism by which lovastatin affects SMAD4.<br />Results: HUVECs infected with KRAS <superscript>G12D</superscript> adenovirus underwent the EndMT. Transforming growth factor beta (TGF-β) and bone morphogenetic protein (BMP) signalling pathways were activated in the KRAS <superscript>G12D</superscript> -mutant HUVECs and ECs in bAVM tissue. Knocking down SMAD4 expression in both KRAS <superscript>G12D</superscript> -mutant HUVECs and ECs in bAVM tissues inhibited the EndMT. Lovastatin attenuated the EndMT by downregulating p-SMAD2/3, p-SMAD1/5 and acetylated SMAD4 expression in KRAS <superscript>G12D</superscript> -mutant HUVECs.<br />Conclusions: Our findings suggest that the KRAS <superscript>G12D</superscript> mutant induces the EndMT by activating the ERK-TGF-β/BMP-SMAD4 signalling pathway and that lovastatin inhibits the EndMT by suppressing TGF-β/BMP pathway activation and SMAD4 acetylation.<br />Competing Interests: Competing interests: None declared.<br /> (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Subjects :
- Humans
Mice
Animals
Proto-Oncogene Proteins p21(ras) metabolism
Zebrafish genetics
Zebrafish metabolism
Human Umbilical Vein Endothelial Cells metabolism
Mutation
Brain metabolism
Smad4 Protein genetics
Smad4 Protein metabolism
Transforming Growth Factor beta metabolism
Intracranial Arteriovenous Malformations genetics
Subjects
Details
- Language :
- English
- ISSN :
- 2059-8696
- Volume :
- 8
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Stroke and vascular neurology
- Publication Type :
- Academic Journal
- Accession number :
- 36418055
- Full Text :
- https://doi.org/10.1136/svn-2022-001700