Joerger-Messerli Marianne S, Thomi Gierin, Haesler Valérie, Keller Irene, Renz Patricia, Surbek Daniel V, Schoeberlein Andreina
Department of Obstetrics and Feto-maternal Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.
Front Cell Dev Biol. 2021 Mar 23;9:622539. doi: 10.3389/fcell.2021.622539. eCollection 2021.
Peripartum cerebral hypoxia and ischemia, and intrauterine infection and inflammation, are detrimental for the precursor cells of the myelin-forming oligodendrocytes in the prematurely newborn, potentially leading to white matter injury (WMI) with long-term neurodevelopmental sequelae. Previous data show that hypomyelination observed in WMI is caused by arrested oligodendroglial maturation rather than oligodendrocyte-specific cell death. In a rat model of premature WMI, we have recently shown that small extracellular vesicles (sEV) derived from Wharton's jelly mesenchymal stromal cells (WJ-MSC) protect from myelination deficits. Thus, we hypothesized that sEV derived from WJ-MSC directly promote oligodendroglial maturation in oligodendrocyte precursor cells. To test this assumption, sEV were isolated from culture supernatants of human WJ-MSC by ultracentrifugation and co-cultured with the human immortalized oligodendrocyte precursor cell line MO3.13. As many regulatory functions in WMI have been ascribed to microRNA (miR) and as sEV are carriers of functional miR which can be delivered to target cells, we characterized and quantified the miR content of WJ-MSC-derived sEV by next-generation sequencing. We found that WJ-MSC-derived sEV co-localized with MO3.13 cells within 4 h. After 5 days of co-culture, the expression of myelin basic protein (MBP), a marker for mature oligodendrocytes, was significantly increased, while the oligodendrocyte precursor marker platelet-derived growth factor alpha (PDGFRα) was decreased. Notch and MAPK/ERK pathways known to inhibit oligodendrocyte maturation and differentiation were significantly reduced. The pathway enrichment analysis showed that the miR present in WJ-MSC-derived sEV target genes having key roles in the MAPK pathway. Our data strongly suggest that sEV from WJ-MSC directly drive the maturation of oligodendrocyte precursor cells by repressing Notch and MAPK/ERK signaling.
围产期脑缺氧缺血以及宫内感染和炎症，对早产新生儿中形成髓鞘的少突胶质细胞的前体细胞有害，可能导致白质损伤（WMI）并伴有长期神经发育后遗症。先前的数据表明，在WMI中观察到的髓鞘形成减少是由少突胶质细胞成熟停滞而非少突胶质细胞特异性细胞死亡引起的。在早产WMI的大鼠模型中，我们最近表明，来自华通氏胶间充质基质细胞（WJ-MSC）的小细胞外囊泡（sEV）可预防髓鞘形成缺陷。因此，我们假设来自WJ-MSC的sEV直接促进少突胶质细胞前体细胞中的少突胶质细胞成熟。为了验证这一假设，通过超速离心从人WJ-MSC的培养上清液中分离出sEV，并与人永生化少突胶质细胞前体细胞系MO3.13共培养。由于WMI中的许多调节功能已归因于微小RNA（miR），并且由于sEV是功能性miR的载体，可被递送至靶细胞，因此我们通过下一代测序对WJ-MSC来源的sEV的miR含量进行了表征和定量。我们发现WJ-MSC来源的sEV在4小时内与MO3.13细胞共定位。共培养5天后，成熟少突胶质细胞的标志物髓鞘碱性蛋白（MBP）的表达显著增加，而少突胶质细胞前体标志物血小板衍生生长因子α（PDGFRα）则减少。已知抑制少突胶质细胞成熟和分化的Notch和MAPK/ERK途径显著减少。通路富集分析表明，WJ-MSC来源的sEV中存在的miR靶向在MAPK途径中起关键作用的基因。我们的数据强烈表明，WJ-MSC来源的sEV通过抑制Notch和MAPK/ERK信号传导直接驱动少突胶质细胞前体细胞的成熟。
