ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90041-B

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractEmbryonic motoneurons were fluorescently‐labelled with carbocyanine (diI) by means of retrograde transport and then grafted into the adult mouse spinal cord (L2) and brain (striatum) for 2–10 weeks. The motoneurons were grafted either following purification on the fluorescence‐activated cell sorter or in the presence of embryonic glial cells and interneurons from the spinal cord. In both conditions of grafting, motoneurons were found to survive and develop in both grey and white matter and were found to migrate long distances in both regions of the central nervous system.Migration of neurons after grafting remains a controversial issue, therefore we have discussed the work of other groups that have described the same phenomenon.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90042-C

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractTo test the hypothesis that transplanted neuronal or neuronal‐like cell lines, grownin vitro, might survive and differentiate in the mammalian spinal grey matter, adult male Sprague‐Dawley rats (N=5) were injected with a suspension of between 3 × 105and 1.0 × 106DiI labeled, undifferentiated rat pheochromocytoma (PC12) cells in sterile phosphate buffered saline. The PC12 cell line was chosen since, in certainin vitroconditions, this cell line serves as a model of neuronal differentiation, which includes the ability to conduct action potentials and form functional synapses. After a survival time of 7 or 8 days, the spinal cords were removed, cryosectioned longitudinally and examined for detection of DiI labeled PC12 cells using fluorescent microscopy. The number of DiI labeled profiles and the proportions of the DiI cells which were differentiated were counted per section in at least five non‐contiguous sections per animal. Differentiation was defined as cells with neurite‐like extensions which exceeded twice the soma diameter. Results demonstrated the following: (1) from 2 to 15% of the transplanted PC12 cells survived (2) migration within the spinal grey matter occurred since PC12 cells were found as much as 510 μm away from the injection site (3) of the surviving PC12 cell population, a proportion of between 60 and 80% were differentiated, many with two or more neurite‐like processes, in all of the rats (4) no mitotic profiles were observed in DiI labelled cells (5) undifferentiated PC12 cells were juxtaposed to the lumens of small blood vessels or within the lesion cavity. Although the specific factors remain to be elucidated, the observed PC12 migration and differentiation within the host spinal grey matter appears to be controlled by factors in the microenvironment. These data support the use of a homogeneousin vitropopulation of neuronal or neuronal‐like cells, which are readily accessible to transfection with the appropriate genes, as transplant sources for the injured spinal cord.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90043-D

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractEmbryonic rabbit corpus callosum transplants were grafted into the thalamus of newborn shiverer mice in order to compare the fates of oligodendroglial and astroglial cells derived from the transplants. Our model allowed the identification of the two populations of macroglial cells. The thalamus was chosen as site of implantation because of its situation at a crossroad of numerous neuronal fascicles. Previous studies, where the dorsal striatum was used as site of implantation, had shown that corpus callosum was one of the favorite routes of migration for both populations of macroglial cells. In the present study special attention was given to the comparison of the migration pathways and areas of settlement of implanted astroglia and oligodendroglia. The internal capsule, the medial lemniscus, the crus cerebri and the thalamic radiations were used by both populations of transplant derived macroglial cells for their migrations through the host parenchyma. They integrated into the host tissue on these routes or further away in areas such as the putamen, the mesencephalon or the colliculi. Signs of degeneration of the implanted astroglia were often observed after 1 month post‐implantation.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90044-E

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe present study examined the fate and migration of transplanted astrocytes in different host ages. Additionally, the effect of donor cell age was examined in relation to cell migration. Cultured astrocytes from 5,12 and 30 daysin vitrowere transplanted into young (postnatal day 5 and 21), adult (4.5 month), and aged (21 month) animals. The transplanted cells were labeled with Fast Blue, Fluorogold or DiI. The results confirmed previous studies demonstrating that transplanted cells were able to migrate successfully through host central nervous system and extended those findings to show that the age of the host significantly influenced donor cell migration distance. Migration was most extensive in young animals, as conditions supporting cell migration appeared to be lacking in older animals. Donor cells preferentially migrated on myelinated fiber tracts, rather than on unmyelinated fiber tracts or gray matter. The donor cells were not glial fibrillary acidic protein positive, indicating that either the cultured type 1 astrocytes did not survive transplantation or underwent significant remodeling of the intermediate filament network. It is also possible that a subpopulation of cells, possibly immature astrocytes which are present in the transplanted cell suspensions, flourished and subsequently migrated in the host brains.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90045-F

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe fate of neonatal glia (mostly glial fibrillary acidic protein‐positive astrocytes), cultured on nitrocellulose papers and implanted into cortical lesion cavities, was examined in adult mice and rats. In mice, a Y‐chromosome‐specific probe andin situhybridization techniques were used to identify male cells. Male‐female grafts allowed visualization of donor glia and their behaviour after transplantation; female‐male grafts allowed an analysis of how host cells responded to the presence of the implants. There was substantial intermixing of cells, with many donor glia migrating away from the implants and host cells migrating onto both sides of the nitrocellulose paper. In rats, donor glia were labelled with fluorescein‐conjugated latex microspheres prior to transplantation on nitrocellulose polymers. The rat data were broadly consistent with those obtained from the mouse: moreover, immunohistochemical studies in rats suggested that the majority of host cells migrating onto the previously cell‐coated papers were astrocytes. In a number of studies, glia‐coated polymers have been used in an attempt to promote the regrowth of axons across lesion sites in the brain and spinal cord. The present work suggests that both transplanted and host glia may influence the regenerative growth seen in such implants.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90046-G

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractNeonatal rat astrocytes transplanted into the rat cerebrum migrate extensively. However, few of the molecular signals determining this migration have been defined. In the present study,in vitromodifications were designed to examine whether differentiation prior to transplantation would affect the magnitude or pattern of astrocyte migration in the neonatal host brain. Here, cortical astrocytes were collected from the brains of rats 1–3 days postpartum and purified by culturing them in DME medium supplemented with 10% calf serum. After 14–21 days, astrocytes were labelled with fluorescein‐tagged latex microspheres for 16 hr; the label was then removed and replaced with either fresh medium or fresh serum‐free medium plus 1 mM dbcAMP. After 48 hr, cells were harvested and then transplanted into the right frontal cerebrum of neonatal rats at 3 days postpartum by injection with a hand‐held Hamilton syringe. Animals were sacrificed at 3, 6, 9, 15, 21 and 28 days after inoculation and their brains examined with fluorescence microscopy. Astrocytes not exposed to dbcAMP prior to implantation migrated along the corpus callosum, internal capsule, glial limitans, ventricular linings and the hippocampal structure. They also appeared to migrate in a radial fashion toward the periphery from the ventricular lining. Astrocytes treated with dbcAMP prior to transplantation did not appear to migrate into the neonatal parenchyma, remaining confined to the injection site for at least 6 days. Migration then appeared to commence at a normal rate after 9 days. Thus, neonatal cortical migrate outward in a pattern similar to that defined by the radial glia. Astrocytes differentiated by dbcAMP treatment, however, do not appear to migrate to any large degree in the neonatal brain until the treatment effect diminishes, suggesting that differentiation may represent an end‐point to glial migration in the neonatal host brain.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90047-H

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractUsing a species‐specific marker, we have found that astrocytes, taken from donors of varying ages from fetal to adult, migrate in highly Stereotypic patterns in immature host brains. Migration is primarily within and towards cell layers, although some cells are seen to migrate along fibre bundles. This contrasts with studies using the same approach in mature hosts, where migration is predominantly within fibre layers, largely excluding cellular regions.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90048-I

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractA demyelinating lesion induced by an injection of lysolecithin into the spinal cord can be partly repaired by oligodendrocyte precursors transplanted at a distance of 6–8 mm from the lesion. Using a non‐toxic fluorescent dye (Hoechst 33342) as a cell marker, we demonstrate that transplanted oligodendrocyte precursors from different origins (periventricular zone fragments from newborn mouse and cultured rat oligodendrocyte progenitor cells) can migrate along specific pathways (i.e. white matter fasciculi, ependymal wall, meninges and blood vessels). These cells can be attracted when passing at the vicinity of the lesion as well as differentiate and remyelinate axons with the lesion. Myelin repair thus appears to be the result of distinct successive events: migration, specific attraction, differentiation and myelination. This can occur in both shiverer and normal adult hosts.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90049-J

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractTo investigate the migration of transplanted glial cells in normal adult mice with a focal demyelinating lesion, we have used A2G mice which have the autosomal dominant Mx‐1 allele as donor. Mx‐1 protein expression is inducible by interferon and is detected in a dotted pattern in the nucleus of A2G cells. A/J mice were used as recipient animals as they express the same major histocompatibility antigens as A2G but cannot express the Mx‐1 protein. An acute demyelinating lesion was produced in the A/J spinal cord by intraspinal injection of lysolecithin. Mixed glial cultures derived from newborn A2G brain were treated with α/β interferon for 24 hr. These Mx‐1 expressing glial cells were then transplanted two intervertebral spaces away from the demyelinating lesion. The fate of the grafted cells was followed over the next 13 days, during which the induced Mx‐1 protein can still be detected by immunocytochemistry. Grafted cells were found between the transplantation site and the lesion at 24 hr and some of the Mx‐1+ cells reached the lesion at 4 days. The majority of the Mx‐1+ migrating cells expressed GFAP and were located in the myelinated white matter and around the blood vessels. Scattered MBP+, Mx‐1+ cells were detected in the lesion indicating that some of the transplanted cells may participate in the repair process. The Mx‐1 is a useful marker to follow the migration events in the days after grafting and to determined what factors may attract transplanted cells toward a demyelinating lesion.

ISSN:0736-5748    

DOI:10.1016/0736-5748(93)90050-N

出版商:Wiley    

年代:2003

数据来源: WILEY