1. Epidermal growth factor and transforming growth factor α down-regulate human gastric lipase gene expression 
Eric Tremblay, Jean René Basque, Nathalie Rivard, Daniel Ménard 
Gastroenterology 
Volume 116, Issue 4, Pages (April 1999)
DOI: /S (99)
Copyright © 1999 American Gastroenterological Association Terms and Conditions

2. Fig. 1
Immunoblotting of HGL. Human fetal gastric total proteins (lanes 1 and 3) and porcine pancreatic lipase (lane 2) were subjected to SDS-PAGE followed by immunoblotting using nitrocellulose membrane. Rabbit antibody directed against HGL was found to react mainly with a 49-kilodalton band corresponding to HGL (lane 1) but not to porcine pancreatic lipase (lane 2). Control nonimmune rabbit serum was negative (lane 3).
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

3. Fig. 2
Immunolocalization of HGL in the (A and D) fundus, (B and E) corpus, and (C and F) antrum regions of the stomach. Frozen sections of (A–C) 13-week-old and (D–F) 20-week-old tissues were stained by indirect immunofluorescence. Between 13 and 20 weeks of gestation, a decreasing gradient of the HGL staining was observed from the fundus to the antrum. (G) Indirect immunofluorescence on 1-μm-thick Lowicryl-embedded gastric tissue from the corpus. Immunoreactive small granules were located in the apical cytoplasm of epithelial cells. (H) Immunoelectron micrograph of apical cytoplasm of a chief (left) and a parietal (right) cell. HGL labeling was detected in the secretory granules of the chief cells (original magnification: A–G, 140×; and H, 20,500×).
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

4. Fig. 3
Developmental expression of HGL. Densitometric analysis of Western and Northern blotting experiments of lipase (HGL) in gastric tissues of 15 and 20 weeks' gestation. Total proteins were separated by SDS-PAGE (12%), electrotransferred onto nitrocellulose membranes, and probed with the anti-HGL and cytokeratin 18 CY-90 monoclonal antibodies. Total RNA (20 μg/lane) was denatured and submitted to electrophoresis on a 1% agarose gel containing 2.2 mol/L formaldehyde, then transferred to a nitrocellulose filter and hybridized with the random-primed HGL and GAPDH cDNA probes. Lipase protein (□) and mRNA (■) levels are expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the cytokeratin 18 and GAPDH signals, respectively. Values represent the means ± SEM of 5 (protein) and 3 (mRNA) separate and independent specimens of each age, respectively. Statistically significant differences between 20 weeks of gestation compared with 15 weeks: *P < 0.005; **P < 0.01.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

5. Fig. 4
Expression of HGL in the different anatomic regions of the stomach. Representative Western and Northern blotting experiments of lipase (HGL) in the fundus (F), corpus (C), and antrum (A). Total proteins and RNAs were prepared as described in Figure 3. Densitometric analysis shows the relative levels of lipase protein (□, 49 kilodaltons) and mRNA (■, 1.6 kb) expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the cytokeratin 18 and GAPDH signals, respectively. Values represent the means ± SEM of 4 separate and independent specimens.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

6. Fig. 5
Expression of HGL in organ culture. Representative Western and Northern blot experiments of lipase (HGL) in gastric explants at the beginning of culture (T0), after 24 hours of culture (Tc), and in the culture medium (Mc, proteins only). Total proteins from gastric tissues and concentrated media as well as total RNAs were prepared as described in Figure 3. Densitometric analysis shows the relative levels of lipase protein (□, 49 kilodaltons) and mRNA (■, 1.6 kb) expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the cytokeratin 18 and GAPDH signals, respectively (for Western blotting, values are reported per milligram of tissue). Values represent the means ± SEM of 3 separate and independent cultures.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

7. Fig. 6
Time-course expression of HGL in organ culture. Densitometric analysis of Northern blots of lipase (HGL) at different times of culture (shaded box represents the stabilization period). Total RNA (20 μg/lane) was prepared as described in Figure 3, and the relative levels of lipase mRNA are expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the GAPDH signals. Values represent the means ± SEM of 3 separate and independent cultures. Statistically significant differences between 0 and 4 hours of culture compared with −4 hours: *P < 0.05; **P <
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

8. Fig. 7
Effect of EGF and TGF-α on the expression of HGL. Densitometric analysis of Northern blots of lipase (HGL) in gastric explants at the beginning of culture (T0) and after 8 hours of culture without supplements (C) or with growth factors (EGF and TGF-α; 100 ng/mL) added immediately after explantation. Total RNA (20 μg/lane) was prepared as described in Figure 3, and the relative levels of lipase mRNA are expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the GAPDH signals. Values represent the means ± SEM of 3 separate and independent cultures. Statistically significant differences between EGF and TGF-α compared with C: *P <
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

9. Fig. 8
Effect of EGF on lipase activity. Lipase activities in gastric explants (■) and culture media (□) at the beginning of culture (T0) and after 24 hours of culture in unsupplemented (C) and EGF-supplemented (100 ng/mL) medium (EGF). Values represent the means ± SEM of 4 separate and independent cultures. Statistically significant difference between EGF compared with C: *P <
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

10. Fig. 9
Variations of MAPK activity in organ culture. Representative Western blot of the biphosphorylated and active forms of p42 and p44 MAPKs in gastric explants at the beginning of culture (T0) and after 8 and 24 hours of culture. Total proteins were prepared as described in Figure 3, and densitometric analysis shows the relative levels of active MAPKs (42 and 44 kilodaltons) expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the cytokeratin 18 signals. Values represent the means ± SEM of 3 independent experiments.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

11. Fig. 10
Effects of EGF, TGF-α, and PD98059 on MAPK activity. Representative Western blot of the biphosphorylated and active forms of p42 and p44 MAPKs in gastric explants after 8 hours of culture without supplements (C), with growth factors (EGF and TGF-α; 100 ng/mL), with PD98059 (PD 20 μmol/L), or with their combinations (EGF/PD and TGF-α/PD). Total proteins were prepared as described in Figure 3, and densitometric analysis shows the relative levels of active MAPKs (42 and 44 kilodaltons) expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the cytokeratin 18 signals. Values represent the means ± SEM of 4 independent experiments.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

12. Fig. 11
Comparative effects of EGF and PD98059 on HGL mRNA. Densitometric analysis of Northern blots of lipase (HGL) in gastric explants after 8 hours of culture without supplements (C), with EGF (100 ng/mL), with PD98059 (PD, 20 μmol/L), or with their combination (EGF/PD). Total RNA (20 μg/lane) was prepared as described in Figure 3, and the relative levels of lipase mRNA (1.6 kb) are expressed in arbitrary units (AU) as the values of densitometric scans of autoradiographs normalized to the GAPDH signals. Values represent the means ± SEM of 5 separate and independent cultures. Statistically significant differences between EGF (*P < 0.025) and PD (**P < 0.01) compared with C are indicated. PD was also significantly different from EGF (P < 0.007).
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions