Mechanical Stress and Alteration of Cellular Morphology Influences O‐GlcNAc Modification

Abstract

Protein O‐linked N‐acetylglucosamine modification (O‐GlcNAc) is the result of a post‐translational modification that involves the reversible transfer of an N‐acetyl‐glucosamine molecule to Ser/Thr OH‐group of intracellular proteins. O‐GlcNAc modification is increasingly recognized as a key regulatory element, capable to modify the functionality and the life‐cycle of hundreds of proteins. O‐GlcNAc's participation in stress adaptation processes was evidenced after several environmental challenges such as heat shock, hypoxia or oxidative stress. However, intracellular O‐GlcNAc modification was not yet studied under mechanical stress, despite the fact that physical stress is a constant challenge for many cells in our body.In our present work, we used human periodontal ligament (PDL) cells isolated from teeth extracted for orthodontic indications. PDL cells were cultivated under standard cell culture conditions and exposed to various amount of compression force for 12 hours.We have analyzed cell survival by flow‐cytometry and protein O‐GlcNAc by Western‐blot. Since cytoskeletal filaments are essential to the structural integrity of the cells both in normal condition and under mechanical stress, we also studied the intracellular distribution of O‐GlcNAc in relation to actin, alpha‐tubulin, vimentin and the cellular shape. We have found that O‐GlcNAc elevated under moderate mechanical load (1.5 – 3 g/cm2) but did not changed significantly under higher load ( ≥ 7 g/cm2). Intracellular distribution of O‐GlcNAc in non‐loaded cell demonstrated an accumulation at several membrane protrusion sites which showed the most overlap with tubulin and no overlap at all with vimentin. Under mechanical stress, the cells retracted these protrusions and O‐GlcNAc distribution became more centralized as well.In conclusion, we found that O‐GlcNAc regulation responds to mechanical challenges and our data suggest that O‐GlcNAc is coupled to cellular morphology.Support or Funding InformationThis work was funded by the Research Fund of the University of Pécs, Faculty of Medicine (grant No.: AOK‐KA 2/2015 (06.30)) and the EU founded Hungarian project GINOP 2.3.2. –15 (grant No.: 2.3.2. –15‐2016‐00050).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.