Homocysteine Metabolites Impair the PHF8/H4K20me1/mTOR/Autophagy Pathway by Upregulating the Expression of Histone Demethylase PHF8-targeting microRNAs in Human Vascular Endothelial Cells and Mice

cris.virtual.author-orcid#PLACEHOLDER_PARENT_METADATA_VALUE#
cris.virtual.author-orcid0000-0001-5845-4409
cris.virtualsource.author-orcid9cfa7201-4c9c-4918-bd81-a322bae987fe
cris.virtualsource.author-orcid4dde7a12-8c22-4e89-9d57-7c74b050ccc5
dc.abstract.enThe inability to efficiently metabolize homocysteine (Hcy) due to nutritional and genetic deficiencies, leads to hyperhomocysteinemia (HHcy) and endothelial dysfunction, a hallmark of atherosclerosis which underpins cardiovascular disease (CVD). PHF8 is a histone demethylase that demethylates H4K20me1, which affects the mammalian target of rapamycin (mTOR) signaling and autophagy, processes that play important roles in CVD. PHF8 is regulated by microRNA (miR) such as miR-22-3p and miR-1229-3p. Biochemically, HHcy is characterized by elevated levels of Hcy, Hcy-thiolactone and N-Hcy-protein. Here, we examined effects of these metabolites on miR-22-3p, miR-1229-3p, and their target PHF8, as well as on the downstream consequences of these effects on H4K20me1, mTOR-, and autophagy-related proteins and mRNAs expression in human umbilical vein endothelial cells (HUVEC). We found that treatments with N-Hcy-protein, Hcy-thiolactone, or Hcy upregulated miR-22-3p and miR-1229-3p, attenuated PHF8 expression, upregulated H4K20me1, mTOR, and phospho-mTOR. Autophagy-related proteins (BECN1, ATG5, ATG7, lipidated LC3-II, and LC3-II/LC3-I ratio) were significantly downregulated by at least one of these metabolites. We also found similar changes in the expression of miR-22-3p, Phf8, mTOR- and autophagy-related proteins/mRNAs in vivo in hearts of Cbs-/- mice, which show severe HHcy and endothelial dysfunction. Treatments with inhibitors of miR-22-3p or miR-1229-3p abrogated the effects of Hcy-thiolactone, N-Hcy-protein, and Hcy on miR expression and on PHF8, H4K20me1, mTOR-, and autophagy-related proteins/mRNAs in HUVEC. Taken together, these findings show that Hcy metabolites upregulate miR-22-3p and miR-1229-3p expression, which then dysregulate the PHF8/H4K20me1/mTOR/autophagy pathway, important for vascular homeostasis.
dc.affiliationWydział Rolnictwa, Ogrodnictwa i Bioinżynierii
dc.affiliation.instituteKatedra Biochemii i Biotechnologii
dc.contributor.authorWitucki, Łukasz
dc.contributor.authorJakubowski, Hieronim
dc.date.access2026-04-08
dc.date.accessioned2026-04-13T09:53:22Z
dc.date.available2026-04-13T09:53:22Z
dc.date.copyright2023-06-27
dc.date.issued2023
dc.description.abstract<jats:title>Abstract</jats:title> <jats:p> The inability to efficiently metabolize homocysteine (Hcy) due to nutritional and genetic deficiencies, leads to hyperhomocysteinemia (HHcy) and endothelial dysfunction, a hallmark of atherosclerosis which underpins cardiovascular disease (CVD). PHF8 is a histone demethylase that demethylates H4K20me1, which affects the mammalian target of rapamycin (mTOR) signaling and autophagy, processes that play important roles in CVD. PHF8 is regulated by microRNA (miR) such as miR-22-3p and miR-1229-3p. Biochemically, HHcy is characterized by elevated levels of Hcy, Hcy-thiolactone and <jats:italic>N</jats:italic> -Hcy-protein. Here, we examined effects of these metabolites on miR-22-3p, miR-1229-3p, and their target PHF8, as well as on the downstream consequences of these effects on H4K20me1, mTOR-, and autophagy-related proteins and mRNAs expression in human umbilical vein endothelial cells (HUVEC). We found that treatments with <jats:italic>N</jats:italic> -Hcy-protein, Hcy-thiolactone, or Hcy upregulated miR-22-3p and miR-1229-3p, attenuated PHF8 expression, upregulated H4K20me1, mTOR, and phospho-mTOR. Autophagy-related proteins (BECN1, ATG5, ATG7, lipidated LC3-II, and LC3-II/LC3-I ratio) were significantly downregulated by at least one of these metabolites. We also found similar changes in the expression of miR-22-3p, Phf8, mTOR- and autophagy-related proteins/mRNAs in vivo in hearts of <jats:italic>Cbs</jats:italic> <jats:sup>-/-</jats:sup> mice, which show severe HHcy and endothelial dysfunction. Treatments with inhibitors of miR-22-3p or miR-1229-3p abrogated the effects of Hcy-thiolactone, <jats:italic>N</jats:italic> -Hcy-protein, and Hcy on miR expression and on PHF8, H4K20me1, mTOR-, and autophagy-related proteins/mRNAs in HUVEC. Taken together, these findings show that Hcy metabolites upregulate miR-22-3p and miR-1229-3p expression, which then dysregulate the PHF8/H4K20me1/mTOR/autophagy pathway, important for vascular homeostasis. </jats:p>
dc.description.accesstimeat_publication
dc.description.bibliographyil., bibliogr.
dc.description.financepublication_nocost
dc.description.financecost0,00
dc.description.versionfinal_published
dc.identifier.doi10.1101/2023.06.27.546759
dc.identifier.urihttps://sciencerep.up.poznan.pl/handle/item/8074
dc.identifier.weblinkhttps://www.biorxiv.org/content/10.1101/2023.06.27.546759v2
dc.languageen
dc.relation.ispartofbioRxiv
dc.rightsCC-BY
dc.sciencecloudnosend
dc.share.typeOPEN_JOURNAL
dc.subject.enhomocysteine thiolactone
dc.subject.enN-homocysteinylated protein
dc.subject.enmicroRNA
dc.subject.enPHF8
dc.subject.enmTOR
dc.subject.enautophagy
dc.subject.enendothelial cells
dc.subtypePublicationInPreprintService
dc.titleHomocysteine Metabolites Impair the PHF8/H4K20me1/mTOR/Autophagy Pathway by Upregulating the Expression of Histone Demethylase PHF8-targeting microRNAs in Human Vascular Endothelial Cells and Mice
dc.typeJournalArticle
dspace.entity.typePublication