1. Induction of Selected Lipid Metabolic Enzymes and Differentiation-Linked Structural Proteins by Air Exposure in Fetal Rat Skin Explants 
László G. Kömüves, Karen Hanley, Yan Jiang, Chika Katagiri, Peter M. Elias, Mary L. Williams, Kenneth R. Feingold 
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
Epidermal HMG CoA reductase and SPT activity decreases during late development in utero and in vitro. Enzyme activity was measured in homogenate (HMG CoA reductase) or microsomal fractions (SPT) of epidermis isolated from fetal rats of gestational age days 17–21 (in utero) or from skin explants taken from gestational day 17 rats and incubated 0–4 d (in vitro submerged) as described in Materials and Methods. Data are presented as mean ± SEM. Similar results were obtained in two separate experiments.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
Air exposure does not affect activity of HMG CoA reductase or SPT in fetal epidermis in vitro. Epidermis was isolated from full-thickness fetal skin explants incubated either submerged or at the air–medium interface (air-exposed) for 1 or 2 d. Activity of HMG CoA reductase (A) or SPT (B) was measured as described in Materials and Methods. Data are expressed as mean ± SEM, n = 4.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

4. Figure 3
GC synthase and CSTase activities are affected by air exposure. GC synthase activity (A) was measured in homogenate and CSTase (B) measured in cytosolic fractions of fetal epidermis isolated from explants incubated for 1 or 2 d either submerged or air-exposed. Average activity in day 17 fetal rat epidermis prior to incubation was 6.5 pmol per min per mg (GC synthase) and 46.6 pmol per h per mg (CSTase). Data are presented as mean ± SEM, *p < 0.01, n = 9.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

5. Figure 4
Induction of steroid sulfatase and β-glucocerebrosidase activity by air exposure. Enzyme activity in epidermis isolated from explants incubated either submerged or air-exposed for 1–4 d was measured as described in Materials and Methods. Average activity in day 17 fetal rat epidermis prior to incubation was 4.9 pmol per min per mg (steroid sulfatase) and 0.98 nmol per min per mg (β-glucocerebrosidase). Data are presented as mean ± SEM, *p < 0.005, n = 8.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

6. Figure 5
Effects of air exposure and occlusion on the expression of profilaggrin and loricrin mRNA in fetal rat skin in vitro. Skin explants from day 17 fetal rats were incubated submerged for 2 d (A, D, G), or incubated air-exposed for 2 d unoccluded (B, E, H) or occluded (C, F, I). Parts (A)–(C) were stained with hematoxylin and eosin. Expression of profilaggrin (D–F) and loricrin (G–I) mRNA was detected by in situ hybridization. The dotted line demarcates the basal lamina of the epidermis, whereas the arrows indicate the epidermal surface. Scale bar: 25 μm.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

7. Figure 6
Effects of air exposure and occlusion on the expression of involucrin, profilaggrin/filaggrin, and loricrin proteins in fetal rat skin in vitro. Fetal rat skin explants were incubated submerged for 2 d (A, D, G), or air-exposed for 2 d unoccluded (B, E, H) or occluded (C, F, I). Presence of involucrin (A–C), profilaggrin/filaggrin (D–F), and loricrin (G–I) proteins were detected by immunohistochemistry. Profilaggrin/filaggrin staining is seen both in the stratum spinosum and in the stratum granulosum, whereas loricrin is localized to the stratum granulosum. The dotted line demarcates the basal lamina of the epidermis, whereas the arrows indicate the epidermal surface. Scale bar: 25 μm.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions

8. Figure 7
Steroid sulfatase and β-glucocerebrosidase activity are not increased by air exposure in occluded explants. Explants were incubated for 2 d either submerged, or air exposed either unoccluded (air) or covered with a water-impermeable membrane (occluded) as described in Materials and Methods. Enzyme activity was measured in epidermal microsomal fractions (A, steroid sulfatase) or homogenates (B, β-glucocerebrosidase) as described in Materials and Methods. Data are expressed as mean ± SEM, n = 6.
Journal of Investigative Dermatology  , DOI: ( /j x)
Copyright © 1999 The Society for Investigative Dermatology, Inc Terms and Conditions