1. Evidence for a Novel Glutamate-Mediated Signaling Pathway in Keratinocytes 
Paul G. Genever, Sarah J. Maxfield, Tim M. Skerry 
Journal of Investigative Dermatology 
Volume 112, Issue 3, Pages (March 1999)
DOI: /j x
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

2. Figure 1
Immunolocalization of glutamate receptors and transporters in normal rat skin cryosections. Distinct pericellular immunoreactivity (brown reaction product) for the NMDAR1 subunit was identified on the surfaces of basal layer keratinocytes in neonatal (a, arrow) and adult (b, arrow) rat epidermis. Weaker NMDAR2A/B staining was also observed on these cells (c, arrow, neonatal rat skin). Staining was absent from all negative control sections (d, neonatal rat skin). AMPA-type GluR2/3 receptors (e, arrowheads, neonatal rat skin) and the AMPA clustering protein, GRIP (f, arrowheads, neonatal rat skin) were co-localized along the basal surfaces of basal keratinocytes. Metabotropic glutamate receptors were expressed by basal layer keratinocytes, with varying intensity along the epidermis. mGluR1α was widely expressed in the basal layer (g, arrow, adult rat skin) but staining levels were markedly reduced or absent in selected keratinocytes (g, arrowheads). Conversely, mGluR2/3 expression was restricted to a small subpopulation of basal keratinocytes (h, arrow, adult rat skin). Specific pericellular immunostaining for the glutamate transporter EAAC1 was present throughout basal layer keratinocytes (i, arrow, neonatal rat skin), whereas the related transporter, GLT-1 was observed in suprabasal cells (j, neonatal rat skin) and absent from basal keratinocytes (j, arrowheads). Hematoxylin counterstain used. Scale bars: 10 μm.[TAB]
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
Reverse transcriptase–PCR amplification of GRIP mRNA from primary human keratinocytes. Specific primers designed from rat GRIP mRNA sequence amplified PCR products of expected size (696 bp) from human brain (lane 1) and human keratinocyte (lane 2) cDNA. Lane 3, negative control.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

4. Figure 3
Immunolocalization of glutamate receptors and transporters during re-epithelialization of full-thickness rat skin wounds. Distinct changes in the distribution of NMDAR1 (a, c, e) and EAAC1 (b, d, f) were observed during epidermal repair. NMDAR1 was only sporadically expressed by migrating keratinocytes in 4 d old (a, arrows) and 8 d old (c, arrow) wounds, whereas EAAC1 immunostaining was widespread throughout the epidermal tongue at 4 d (b) and 8 d (d) post-wounding. Sixteen days after wounding, NMDAR1 was re-expressed by basal layer keratinocytes in the repaired epidermis (e, arrow), and EAAC1 displayed diminished suprabasal staining (f). ME, migrating epidermis. Hematoxylin counterstain used. Scale bars: 25 μm (a–d); 10 μm (e, f).
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

5. Figure 4
Epidermal NMDAR1 immunolocalization during rat embryonic development. NMDAR1 immunoreactivity was observed throughout all epidermal layers in E14 (a) and E16 (b) embryos. In E18 embryos, NMDAR1 expression was restricted to basal layer keratinocytes (c, arrow). Hematoxylin counterstain used. Scale bars: 10 μm.[TAB]
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

6. Figure 5
Effect of NMDA receptor blockade on cultured keratinocytes. Primary human keratinocytes were cultured in low Ca2+-containing medium for 7 d (a, b) and 11 d (c, d) in the absence (a, c) or presence (b, d) of MK-801 (100 μM) a specific NMDA receptor antagonist. In 7 d old control cultures, cells were sparse (a) compared with MK-801-treated cultures, which appeared to accumulate in piles (b). By day 11, control cultures had formed numerous monolayered colonies with a typical cobblestone appearance (c), whereas MK-801-treated cells displayed little evidence of colony formation and continued to multilayer (d). Representative fields shown, scale bars: 30 μM.[TAB]
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions