PMID- 30870435 OWN - NLM STAT- MEDLINE DCOM- 20191203 LR - 20200309 IS - 1932-6203 (Electronic) IS - 1932-6203 (Linking) VI - 14 IP - 3 DP - 2019 TI - Defining the role of NG2-expressing cells in experimental models of multiple sclerosis. A biofunctional analysis of the neurovascular unit in wild type and NG2 null mice. PG - e0213508 LID - 10.1371/journal.pone.0213508 [doi] LID - e0213508 AB - During experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis associated with blood-brain barrier (BBB) disruption, oligodendrocyte precursor cells (OPCs) overexpress proteoglycan nerve/glial antigen 2 (NG2), proliferate, and make contacts with the microvessel wall. To explore whether OPCs may actually be recruited within the neurovascular unit (NVU), de facto intervening in its cellular and molecular composition, we quantified by immunoconfocal morphometry the presence of OPCs in contact with brain microvessels, during postnatal cerebral cortex vascularization at postnatal day 6, in wild-type (WT) and NG2 knock-out (NG2KO) mice, and in the cortex of adult naive and EAE-affected WT and NG2KO mice. As observed in WT mice during postnatal development, a higher number of juxtavascular and perivascular OPCs was revealed in adult WT mice during EAE compared to adult naive WT mice. In EAE-affected mice, OPCs were mostly associated with microvessels that showed altered claudin-5 and occludin tight junction (TJ) staining patterns and barrier leakage. In contrast, EAE-affected NG2KO mice, which did not show any significant increase in vessel-associated OPCs, seemed to retain better preserved TJs and BBB integrity. As expected, absence of NG2, in both OPCs and pericytes, led to a reduced content of vessel basal lamina molecules, laminin, collagen VI, and collagen IV. In addition, analysis of the major ligand/receptor systems known to promote OPC proliferation and migration indicated that vascular endothelial growth factor A (VEGF-A), platelet-derived growth factor-AA (PDGF-AA), and the transforming growth factor-beta (TGF-beta) were the molecules most likely involved in proliferation and recruitment of vascular OPCs during EAE. These results were confirmed by real time-PCR that showed Fgf2, Pdgfa and Tgfb expression on isolated cerebral cortex microvessels and by dual RNAscope-immunohistochemistry/in situ hybridization (IHC/ISH), which detected Vegfa and Vegfr2 transcripts on cerebral cortex sections. Overall, this study suggests that vascular OPCs, in virtue of their developmental arrangement and response to neuroinflammation and growth factors, could be integrated among the classical NVU cell components. Moreover, the synchronized activation of vascular OPCs and pericytes during both BBB development and dysfunction, points to NG2 as a key regulator of vascular interactions. FAU - Girolamo, Francesco AU - Girolamo F AUID- ORCID: 0000-0001-8706-3386 AD - Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy. FAU - Errede, Mariella AU - Errede M AD - Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy. FAU - Longo, Giovanna AU - Longo G AD - Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy. FAU - Annese, Tiziana AU - Annese T AD - Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy. FAU - Alias, Carlotta AU - Alias C AD - B+LabNet-Environmental Sustainability Lab, University of Brescia, Brescia, Italy. FAU - Ferrara, Giovanni AU - Ferrara G AUID- ORCID: 0000-0002-4442-8864 AD - Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy. FAU - Morando, Sara AU - Morando S AD - Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy. FAU - Trojano, Maria AU - Trojano M AD - Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy. FAU - Kerlero de Rosbo, Nicole AU - Kerlero de Rosbo N AD - Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy. FAU - Uccelli, Antonio AU - Uccelli A AD - Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy. AD - Center of Excellence for Biomedical Research (CEBR), University of Genoa, Genoa, Italy. AD - Ospedale Policlinico San Martino-IRCCS, Genoa, Italy. FAU - Virgintino, Daniela AU - Virgintino D AD - Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20190314 PL - United States TA - PLoS One JT - PloS one JID - 101285081 RN - 0 (Antigens) RN - 0 (Claudin-5) RN - 0 (Cldn5 protein, mouse) RN - 0 (Platelet-Derived Growth Factor) RN - 0 (Proteoglycans) RN - 0 (Transforming Growth Factor beta) RN - 0 (Vascular Endothelial Growth Factor A) RN - 0 (chondroitin sulfate proteoglycan 4) RN - 0 (platelet-derived growth factor A) RN - 0 (vascular endothelial growth factor A, mouse) SB - IM MH - Animals MH - Antigens/*biosynthesis/genetics MH - Blood-Brain Barrier/*metabolism/pathology MH - Cell Movement/genetics MH - Cell Proliferation/genetics MH - Cerebral Cortex/blood supply/metabolism/pathology MH - Claudin-5/genetics/metabolism MH - Disease Models, Animal MH - Encephalomyelitis, Autoimmune, Experimental/genetics/*metabolism/pathology MH - Mice MH - Mice, Knockout MH - Microvessels/*metabolism/pathology MH - Oligodendroglia/*metabolism/pathology MH - Platelet-Derived Growth Factor/genetics/metabolism MH - Proteoglycans/*biosynthesis/genetics MH - Stem Cells/*metabolism/pathology MH - Tight Junctions/genetics/metabolism/pathology MH - Transforming Growth Factor beta/genetics/metabolism MH - Vascular Endothelial Growth Factor A/genetics/metabolism PMC - PMC6417733 COIS- The authors have declared that no competing interests exist. EDAT- 2019/03/15 06:00 MHDA- 2019/12/04 06:00 PMCR- 2019/03/14 CRDT- 2019/03/15 06:00 PHST- 2018/06/13 00:00 [received] PHST- 2019/02/24 00:00 [accepted] PHST- 2019/03/15 06:00 [entrez] PHST- 2019/03/15 06:00 [pubmed] PHST- 2019/12/04 06:00 [medline] PHST- 2019/03/14 00:00 [pmc-release] AID - PONE-D-18-17750 [pii] AID - 10.1371/journal.pone.0213508 [doi] PST - epublish SO - PLoS One. 2019 Mar 14;14(3):e0213508. doi: 10.1371/journal.pone.0213508. eCollection 2019.