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- Baier, Claudia, et al.
(författare)
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Hyaluronan is organized into fiber-like structures along migratory pathways in the developing mouse cerebellum
- 2007
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Ingår i: Matrix Biology. - : Elsevier BV. - 1569-1802 .- 0945-053X. ; 26:5, s. 348-358
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Tidskriftsartikel (refereegranskat)abstract
- Hyaluronan is a free glycosaminoglycan which is abundant in the extracellular matrix of the developing brain. Although not covalently linked to any protein it can act as a backbone molecule forming aggregates with chondroitin sulfate proteoglycans of the lectican family and link proteins. Using neurocan-GFP as a direct histochemical probe we analyzed the distribution and organization of hyaluronan in the developing mouse cerebellum, and related its fine structure to cell types of specified developmental stages. We observed a high affinity of this probe to fiber-like structures in the prospective white matter which are preferentially oriented parallel to the cerebellar cortex during postnatal development suggesting a specially organized form of hyaluronan. In other layers of the cerebellar cortex, the hyaluronan organization seemed to be more diffuse. During the second postnatal week, the overall staining intensity of hyaluronan in the white matter declined but fiber-like structures were still present at the adult stage. This type of hyaluronan organization is different from perineuronal nets e.g. found in deep cerebellar nuclei. Double staining experiments with cell type specific markers indicated that these fiber-like structures are predominantly situated in regions where motile cells such as Pax2-positive inhibitory interneuron precursors and MBP-positive oligodendroglial cells are located. In contrast, more stationary cells such as mature granule cells and Purkinje cells are associated with lower levels of hyaluronan in their environment. Thus, hyaluronan-rich fibers are concentrated at sites where specific neural precursor cell types migrate, and the anisotropic orientation of these fibers suggests that they may support guided neural migration during brain development. (c) 2007 Elsevier B.V./International Society of Matrix Biology. All rights reserved.
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| 2. |
- Kappler, Joachim, et al.
(författare)
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Transport of a hyaluronan-binding protein in brain tissue
- 2009
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Ingår i: Matrix Biology. - : Elsevier BV. - 1569-1802 .- 0945-053X. ; 28:7, s. 396-405
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Tidskriftsartikel (refereegranskat)abstract
- Hyaluronan is an unsulfated linear glycosaminoglycan with the ability to nucleate extracellular matrices by the formation of aggregates with lecticans. These matrices are essential during development of the central nervous system. In the prospective white matter of the developing brain hyaluronan is organized into fiber-like structures according to confocal microscopy of fixed slices which may guide the migration of neural precursor cells [Baier, C., S.L Baader, J. Jankowski, V. Gieselmann, K. Schilling, U. Rauch, and J. Kappler. 2007. Hyaluronan is organized into fiber-like structures along migratory pathways in the developing mouse cerebellum. Matrix Biol. 26: 348-58]. By using plasmon surface resonance, microinjection into brain slices and fluorescence correlation spectroscopy, we show that the brain-specific lecticans bind to, but also dissociate rather rapidly from hyaluronan. After microinjection into native cerebellar slices a GFP-tagged hyaluronan-binding neurocan fragment was enriched at binding sites in the prospective white matter, which had a directional orientation and formed local stationary concentration gradients in areas where binding sites are abundant. Fluorescence correlation spectroscopy measurements at fixed brain slices revealed that fiber-bound neurocan-GFP was mobile with Dfiber(neurocan-GFP) = 4 x 10(-10) cm(2)/s. Therefore, we propose that hyaluronan-rich fibers in the prospective white matter of the developing mouse cerebellum can guide the diffusion of lecticans. Since lecticans bind a variety of growth and mobility factors, their guided diffusion may contribute to the transport of these polypeptides and to the formation of concentration gradients. This mechanism could serve to encode positional information during development. (C) 2009 Elsevier B.V. All rights reserved.
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