Protein O-mannosylation is crucial for human mesencyhmal stem cells fate

Abstract

Human mesenchymal stem cells (MSC) are promising cell types in the field of regenerative medicine. Although many pathways have been dissected in the effort to better understand and characterize MSC potential, the impact of protein N- or O-glycosylation has been neglected. Deficient protein O-mannosylation is a pathomechanism underlying severe congenital muscular dystrophies (CMD) that start to develop at the embryonic developmental stage and progress in the adult, often in tissues where MSC exert their function. Here we show that O-mannosylation genes, many of which are putative or verified glycosyltransferases (GTs), are expressed in a similar pattern in MSC from adipose tissue, bone marrow, and umbilical cord blood and that their expression levels are retained constant during mesengenic differentiation. Inhibition of the first players of the enzymatic cascade, POMT1/2, resulted in complete abolishment of chondrogenesis and alterations of adipogenic and osteogenic potential together with a lethal effect during myogenic induction. Since to date, no therapy for CMD is available, we explored the possibility of using MSC extracellular vesicles (EVs) as molecular source of functional GTs mRNA. All MSC secrete POMT1 mRNA-containing EVs that are able to efficiently fuse with myoblasts which are among the most affected cells by CMD. Intriguingly, in a pomt1 patient myoblast line EVs were able to partially revert O-mannosylation deficiency and contribute to a morphology recovery. Altogether, these results emphasize the crucial role of protein O-mannosylation in stem cell fate and properties and open the possibility of using MSC vesicles as a novel therapeutic approach to CMD.

Lost in translation: egg transcriptome reveals molecular signature to predict developmental success and novel maternal-effect genes

“…2a-h and Additional file 3, respectively). Literature search showed that most of these genes have known functions: tk2 [36] is a deoxyribonucleoside kinase that is required for mitochondrial DNA synthesis; drd3 [37] is dopamine receptor which is associated with cognitive, emotional, and endocrine functions; cldn23 [38] is an integral membrane protein that maintains cell polarity and signal transductions; nudt13 [39] is hydrolase and its function is also largely unknown; itih2 [40] is a serine protease inhibitor that carries hyaluronan in plasma; flvcr1 [41] is a heme transporter that has a critical role in erythropoiesis by protecting developing erythroid cells from heme toxicity; pomt1 [42] is an O-mannosyltransferase that is a component of many polysaccharides and glycoproteins; prkcq [43] is a serine- and threonine-specific protein kinase that is important for T-cell activation; and otulina [44] is a predicted deubiquitinase also called fam105ba . qPCR confirmed the differential expression of these genes in bad quality eggs relative to good quality eggs (Fig.…”

Extracellular Vesicle-Shuttled mRNA in Mesenchymal Stem Cell Communication

“…It has been reported previously that MSC-EVs contain mRNAs [15,[20][21][22][23]. While these studies identified some of the encapsulated transcripts, they did not assess their relative expression levels or the ratios between different EV isolates.…”

“…MSC from bone marrow aspirate and umbilical cord blood were obtained from healthy donors after informed consent. MSC isolation was performed as described in Ragni et al . MSC were propagated in alpha MEM supplemented with 20% Fetal Bovine Serum (FBS) (Life Technologies, Carlsbad, CA, https://www.thermofisher.com/).…”

Low-affinity Nerve Growth Factor Receptor (CD271) Heterogeneous Expression in Adult and Fetal Mesenchymal Stromal Cells

“…Each stromal population type was isolated from eight independent healthy donors, as previously described for ADMSC, BMMSC 46 and CBMSC (Long Living (LL-)CBMSC 9 ), for AFC 48 , for PVC 49 , for WJMSC 50 . Three human skin fibroblasts (HSF) were also used 51 . Donors’ age was 55 ± 5 years for ADMSC, 33 ± 20 years for BMMSC, 48 ± 12 years for HSF, 38–42 gestational weeks for CBMSC, 16 gestational weeks for AFC, 30–33 gestational weeks for PVC, 38–42 gestational weeks for WJMSC.…”