Laminin is induced in astrocytes of adult brain by injury.

Abstract

Laminin is a high mol. wt. non-collagenous matrix glycoprotein, confined in adult tissues to basement membranes. In normal rat brain we found laminin mainly in vessel walls but, after injury, induced by stereotaxic injection of a neurotoxin, laminin immunoreactivity appeared also in reactive astrocytes, which are characteristically positive for the glial fibrillary acidic protein (GFAP). Laminin was first detected in GFAPimmunoreactive glial cells 24 h after injury. Four days later the majority of reactive astrocytes in the gray matter were positive for laminin and the laminin immunoreactivity, but not that of GFAP, gradually subsided within a month. Fibronectin, the other major matrix glycoprotein, was found only in capillary structures both in normal and lesioned brain tissue. The results indicate that mature astrocytes have the potential to produce laminin and suggest a role for this glycoprotein in brain regeneration.

Do neurons in the vertebrate CNS migrate on laminin?

“…Post-natal rats were anaesthetised with tribromoethanol, the brains fixed with 0.4% BQ in PBS for 2 min using transcardial perfusion, and then prepared for cryostat sections in the sagittal plane. Light microscopic immunocytochemistryfor laninin, vimentin, GFAP andfibronectin The cryostat sections were air-dried for 1 h before rinsing them in PBS followed by dehydration and rehydration as described (Liesi et al, 1984a). The sections were incubated ovemight at +40C with nonral sheep serum diluted 1/30.…”

“…Second, although absent from adult brain glia, laminin is transiently produced by astrocytes both in culture and in vivo after brain injury (Liesi et al, 1984a). Third, when presented as a substrate molecule, laminin promotes spreading and neurite outgrowth of both peripheral and central neurons (Baron-Van Evercooren et al, 1982;Rogers et al, 1983;Manthorpe et al, 1983;Liesi et al, 1984b;Edgar et al, 1984).…”

Three-Dimensional Neural Spheroid Culture: AnIn VitroModel for Cortical Studies

“…[38][39][40] In many scaffold-based cultures, the scaffold introduces foreign ECM to the microenvironment, which can potentially modify cell behavior and mask disease-related changes in the culture model. In the spheroids of this work, the cells produced all of the ECM.…”

Post-traumatic inflammation following spinal cord injury

“…Specifically, reactive astrogliosis is denoted by increased immunoreactivity of glial fibrillary acid protein (GFAP), which is a distinct cellular marker of astrocytes. 14,48,[71][72][73][74]111 It has been demonstrated that reactive adult astrocytes upregulate the production of laminin and neurotrophin C. 75,76 In addition to the endogenously present myelinassociated neurite growth inhibitory constitutents, reactive astrocytes form an astroglial scar that acts as a physical and/or chemical barrier to axonal regeneration. 8,35,72,77,78 Proximity to the lesion epicentre determines whether the reactive glial environment will be growth supportive or inhibitory.…”