Change search
ReferencesLink to record
Permanent link

Direct link
The absence of CD47 promotes nerve fiber growth from cultured ventral mesencephalic dopamine neurons
Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
Kobe University Graduate School of Medicine.
Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
Show others and affiliations
2012 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 7, no 9, e45218- p.Article in journal (Refereed) Published
Abstract [en]

In ventral mesencephalic organotypic tissue cultures, two timely separated sequences of nerve fiber growth have been observed. The first appearing nerve fiber pattern is a long-distance outgrowth that occurs before astrocytes start to proliferate and migrate to form an astrocytic monolayer that finally surrounds the tissue slice. These long-distance growing nerve fibers are retracted as the astrocytes migrate, and are followed by a secondary outgrowth. The secondary outgrowth is persistent in time but reaches short distances, comparable with outgrowth seen from a dopaminergic graft implanted to the brain. The present study was focused on the interaction between the astrocytes and the long-distance growing non-glial associated nerve fibers. Cross talk between astroglia and neurite formation might occur through the integrin-associated protein CD47. CD47 serves as a ligand for signal regulatory protein (SIRP) alpha and as a receptor for the extracellular matrix protein thrombospondin-1 (TSP-1). Embryonic day 14 ventral mesencephalic tissue from CD47(+/+) and CD47(-/-) mice was used to investigate astrocytic migration and the tyrosine hydroxylase (TH) -positive outgrowth that occurred remote from the astrocytes. TH-immunohistochemistry demonstrated that the non-glial-associated nerve fiber outgrowth in CD47(-/-) cultures reached significantly longer distances and higher density compared to nerve fibers formed in CD47(+/+) cultures at 14 days in vitro. These nerve fibers often had a dotted appearance in CD47(+/+) cultures. No difference in the astrocytic migration was observed. Further investigations revealed that the presence of CD47 in control culture did neither hamper non-glial-associated growth through SIRP alpha nor through TSP-1 since similar outgrowth was found in SIRP alpha mutant cultures and in CD47(+/+) cultures treated with blocking antibodies against the TSP-1, respectively, as in the control cultures. In conclusion, long-distance growing nerve fiber formation is promoted by the absence of CD47, even though the presence of astrocytes is not inhibited.

Place, publisher, year, edition, pages
Public library of science , 2012. Vol. 7, no 9, e45218- p.
National Category
Cell Biology
URN: urn:nbn:se:umu:diva-61571DOI: 10.1371/journal.pone.0045218ISI: 000309517300019OAI: diva2:581663
Available from: 2013-01-02 Created: 2012-11-20 Last updated: 2014-05-07Bibliographically approved
In thesis
1. Interaction between nerve fiber formation and astrocytes
Open this publication in new window or tab >>Interaction between nerve fiber formation and astrocytes
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Parkinson’s disease, the second most common neurodegenerative disorder,is characterized by loss of nigrostriatal dopaminergic neurons. To date,there is no defined cause and cure for the disease. An ideal treatmentstrategy is to replace the lost neurons by transplanting fetal dopaminergicneurons to the brain of parkinsonian patients. Clinical trials have beenperformed and the outcome was variable where one significant obstaclewas the limited graft reinnervation of the host brain. To study this issue,organotypic tissue culture can be utilized to monitor dopaminergic nervefiber outgrowth in vitro and their association with astrocytes. Using thisculture technique, dopaminergic nerve fibers appear in twomorphologically and temporally different types. The early appearing nervefibers are formed in the absence of astrocytes, reach long distances, andare called non-glial-associated tyrosine hydroxylase (TH) -positive nervefibers. After a few days, the second sequence of nerve fibers, the glialassociatedTH-positive nerve fibers, are formed, and their growth arelimited to the presence of astrocytes, that migrate and form a monolayersurrounding the plated tissue. The aim of this thesis was to study theinteraction between nerve fiber formation and astrocytes with a specialfocus on the long-distance growing nerve fibers. Ventral mesencephalic(VM) organotypic slice cultures from embryonic day (E) 12, E14, and E18were incubated for 14, 21, 28, and 35 days in vitro (DIV). The resultsrevealed that the two morphologically different processes were found incultures from the younger stages, while no non-glial-associated growthwas found in cultures of tissue from E18. Instead neurons had migratedonto the migrating astrocytes. Astrocytes migrated longer distances intissue from older stages, and the migration reached a plateau at 21 DIV.Co-cultures of E14 VM tissue pieces and cell suspension of matureastrocytes promoted migration of neurons, as seen in E18 cultures. Thus,9the maturity of the astrocytes was an important factor for nerve fiberoutgrowth. Hence, targeting molecules secreted by astrocytes might bebeneficial for regeneration. Chondroitin sulfate proteoglycan (CSPG), amember of proteoglycan family, is produced by the astrocytes and has adual role of being permissive during development and inhibitory afterbrain injury in adult brain. Cultures were treated with chondroitinase ABC(ChABC) or methyl-umbelliferyl-β-D-xyloside (β-xyloside) in twodifferent protocols, early and late treatments. The results from the earlytreated cultures showed that both compounds inhibited the outgrowth ofnerve fibers and astrocytic migration in cultures from E14 tissue, while β-xyloside but not ChABC promoted the non-glial-associated growth incultures derived from E18 fetuses. In addition, β-xyloside but not ChABCinhibited neuronal migration in E18 cultures. Taken together, β-xylosideappeared more effective than ChABC in promoting nerve fiber growth.Another potential candidate, integrin-associated protein CD47, was studiedbecause of its role in synaptogenesis, which is important for nerve fibergrowth. Cultures from E14 CD47 knockout (CD47-/-) mice were plated andcompared to their wildtypes. CD47-/- cultures displayed a massive and longnon-glial-associated TH-positive nerve fiber outgrowth despite theirnormal astrocytic migration. Blocking either signal regulatory protein-α(SIRPα) or thrombospondin-1 (TSP-1), which bind to CD47, had nogrowth promoting effect. In conclusion, to promote nerve growth, youngertissue can grow for longer distances than older tissue, and inhibiting CSPGproduction promotes nerve growth in older tissue, while gene deletion ofCD47 makes the astrocytes permissive for a robust nerve fiber growth.

Place, publisher, year, edition, pages
Umeå: Umeå Universitet, 2014. 56 p.
Umeå University medical dissertations, ISSN 0346-6612 ; 1650
dopamine, nerve fiber outgrowth, astrocytes, ventral mesencephalon, spinal cord, CSPG, CD47
National Category
urn:nbn:se:umu:diva-88366 (URN)978-91-7601-057-0 (ISBN)
Public defence
2014-05-28, BiA201, Biologihuset, Umeå Universitet, Umeå, 09:00 (English)
Available from: 2014-05-07 Created: 2014-05-05 Last updated: 2014-05-07Bibliographically approved

Open Access in DiVA

fulltext(1161 kB)50 downloads
File information
File name FULLTEXT01.pdfFile size 1161 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Marschinke, FranziskaHashemian, Sanaz AlsadatOldenborg, Per-ArneStrömberg, Ingrid
By organisation
Histology and Cell Biology
In the same journal
Cell Biology

Search outside of DiVA

GoogleGoogle Scholar
Total: 50 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 113 hits
ReferencesLink to record
Permanent link

Direct link