scholarly journals Type 1 neurofibromatosis: selective expression of extracellular matrix genes by Schwann cells, perineurial cells, and fibroblasts in mixed cultures.

1989 ◽  
Vol 84 (1) ◽  
pp. 253-261 ◽  
Author(s):  
S Jaakkola ◽  
J Peltonen ◽  
V Riccardi ◽  
M L Chu ◽  
J Uitto
Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3583-3592
Author(s):  
T. Rosenbaum ◽  
Y.L. Boissy ◽  
K. Kombrinck ◽  
C.I. Brannan ◽  
N.A. Jenkins ◽  
...  

To identify cell type(s) that might contribute to nerve sheath tumors (neurofibromas) in patients with neurofibromatosis type 1, we generated cell cultures containing neurons. Schwann cells and fibroblasts from transgenic mouse embryos in which the type 1 neurofibromatosis gene was disrupted by homologous recombination (Brannan et al. (1994) Genes Development, 8,1019-1029). Normal fascicle formation by perineurial cells failed to occur in the absence of neurofibromin. Fascicles were reduced in number and showed abnormal morphology when normal neurons and Schwann cells were cultured up to 37 days with fibroblasts lacking neurofibromin. Proliferation was increased in a majority of fibroblast cell strains analyzed from embryos lacking neurofibromin. These observations suggest that mutations in the neurofibromatosis type I gene affect fibroblast behavior that might contribute to neurofibroma formation in patients with neurofibromatosis type 1.


1989 ◽  
Vol 108 (3) ◽  
pp. 1157-1163 ◽  
Author(s):  
S Jaakkola ◽  
J Peltonen ◽  
J J Uitto

Perineurial cell cultures were established from the sciatic nerves of adult Wistar rats. Highly enriched cultures were studied with respect to the production of extracellular matrix components under conditions free from the influence of Schwann cells, axons, or the extracellular matrix of peripheral nerves. Indirect immunofluorescence staining revealed the presence of collagen type IV epitopes, and electron microscopy demonstrated patches of basement membrane on the perineurial cell surfaces. Collagenous fibrils with a diameter of 15-20 nm were also observed in the intracellular space. SDS-PAGE of radiolabeled medium proteins showed a pattern of bands suggesting the synthesis and secretion of fibronectin, and type I and IV collagens. Northern hybridizations revealed characteristic polymorphic mRNA transcripts corresponding to fibronectin, laminin B2 chain, as well as to the alpha-chain subunits of type I, III, and IV collagens. Furthermore, in situ hybridizations suggested expression of these genes by cultured perineurial cells without apparent heterogeneity within the cell populations. In situ hybridizations of sciatic nerve tissue from 2-wk-old rats also suggested that perineurial cells express alpha 1(I) and alpha 2(IV) collagen, as well as laminin B2 chain genes in vivo. This profile of matrix gene expression is different from that of Schwann cells, which do not synthesize fibronectin, or that of fibroblastic cells, which do not form a cell surface basement membrane. The capability of perineurial cells to express genes for the basement membrane zone and for interstitial collagens further adds to our understanding of the functional role of perineurial cells in developing and healing peripheral nerve, as well as in certain neoplastic lesions of neural origin, such as von Recklinghausen's neurofibromas.


Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 479
Author(s):  
Ahad M. Siddiqui ◽  
Rosa Brunner ◽  
Gregory M. Harris ◽  
Alan Lee Miller ◽  
Brian E. Waletzki ◽  
...  

Spinal cord injury (SCI) results in cell death, demyelination, and axonal loss. The spinal cord has a limited ability to regenerate, and current clinical therapies for SCI are not effective in helping promote neurologic recovery. We have developed a novel scaffold biomaterial that is fabricated from the biodegradable hydrogel oligo(poly(ethylene glycol)fumarate) (OPF). We have previously shown that positively charged OPF scaffolds (OPF+) in an open spaced, multichannel design can be loaded with Schwann cells to support axonal generation and functional recovery following SCI. We have now developed a hybrid OPF+ biomaterial that increases the surface area available for cell attachment and that contains an aligned microarchitecture and extracellular matrix (ECM) proteins to better support axonal regeneration. OPF+ was fabricated as 0.08 mm thick sheets containing 100 μm high polymer ridges that self-assemble into a spiral shape when hydrated. Laminin, fibronectin, or collagen I coating promoted neuron attachment and axonal outgrowth on the scaffold surface. In addition, the ridges aligned axons in a longitudinal bipolar orientation. Decreasing the space between the ridges increased the number of cells and neurites aligned in the direction of the ridge. Schwann cells seeded on laminin coated OPF+ sheets aligned along the ridges over a 6-day period and could myelinate dorsal root ganglion neurons over 4 weeks. This novel scaffold design, with closer spaced ridges and Schwann cells, is a novel biomaterial construct to promote regeneration after SCI.


Heart Asia ◽  
2012 ◽  
Vol 4 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Amit Malviya ◽  
Sundeep Mishra ◽  
Shyam S Kothari

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