FIG. 5.

Protoplasmic and fibrous astrocytes have distinct ECM composition. (A) Graphical representation of proteomics results. Each point represents the average spectral count of the identified protein from two independent runs. Lines denote one, two, or three standard deviations away from equal spectral count of the specific protein detected. Proteins found to be significantly different between protoplasmic and fibrous ECMs are denoted by green squares, Fisher's exact test with Benjamini–Hochberg correction, P < 0.001, n = 2. Orange squares denote proteins that did not differ significantly between astrocyte ECMs. (A′) Blowup of indicated area in (A). Red circles mark proteins of interest: 1: spondin-1, 2: collagen XIIα1, 3: perlecan, 4: neurocan, 5: versican, 6: laminin α5. (B) Confirmation of proteomics findings for spondin-1, collagen XIIα1, and perlecan with immunohistochemistry (target protein in green and nuclei in blue) showing an expression pattern consistent with the proteomics data. Scale bar = 100 μm. (C) Western blots of ECMs harvested from decellularized plates also show the expected pattern spondin-1, collagen XIIα1, and perlecan. F: Fibrous ECM, P: protoplasmic ECM, Arrowhead denotes protein band. ECM, extracellular matrix. Color images available online at www.liebertpub.com/scd