1. Volume 116, Issue 5, Pages 1155-1166 (May 1999)
Intracellular pathways mediating Na+/H+ exchange activation by platelet-derived growth factor in rat hepatic stellate cells 
Antonio Di Sario*, Emanuele Bendia*, Gianluca Svegliati Baroni*, Francesco Ridolfi*, Laura Bolognini*, Giuseppe Feliciangeli*, Anne Marie Jezequel‡, Francesco Orlandi*, Antonio Benedetti* 
Gastroenterology 
Volume 116, Issue 5, Pages (May 1999)
DOI: /S (99)
Copyright © 1999 American Gastroenterological Association Terms and Conditions

2. Fig. 1
(A) Na+/H+ exchange activity, expressed as H+ efflux (JH+)/min, in controls and PDGF-treated HSCs in the absence (vehicle) and presence of inhibitors of the calcium/calmodulin pathway. As evident, preincubation with these inhibitors prevented PDGF-induced Na+/H+ exchange activation in HSCs. *P < 0.01 vs. other groups. (B) HSC proliferation, expressed as percentage of BrdU-positive cells, in controls and PDGF-treated HSCs in the absence (vehicle) and presence of inhibitors of the calcium/calmodulin pathway. Preincubation with these inhibitors significantly inhibited PDGF-induced HSC proliferation. *P < vs. other groups.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

3. Fig. 2
Correlation between maximal H+ efflux (JH+)/min and nadir pHi values in controls (○) and in PDGF-treated cells (●). The intercept of the curve with y-axis represents the H+ efflux, whereas the intercept with x-axis represents the pHi set-point. The slope of the curve is a measure of the pHi dependence of pHi recovery.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

4. Fig. 3
(A) y-axis intercept values in controls and PDGF-treated HSCs in the absence (vehicle) and presence of the inhibitors of the main intracellular pathways. As clearly shown, calphostin C and KN-62, but not wortmannin and PD 98059, reduced y-axis intercept values to that of controls. *P < vs. controls, calphostin C, and KN-62. (B) Slope values in controls and in PDGF-treated HSCs in the absence (vehicle) and presence of the inhibitors of the main intracellular pathways. Preincubation of HSCs with calphostin C and KN-62, but not with wortmannin and PD 98059, reduced the slope values to that of controls. *P < vs. controls, calphostin C, and KN-62.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

5. Fig. 4
Immunoblot of membrane proteins of HSCs treated with or without 25 ng/mL PDGF for 24 hours. Membrane proteins were separated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, transferred to nitrocellulose, and revealed with the specific Na+/H+ exchange antibody, as described in Materials and Methods. A major band of about 110 kilodaltons was observed both in the control group and in HSCs incubated with PDGF and was quantified by densitometry. The blot is representative of 3 different experiments.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

6. Fig. 5
(A) Na+/H+ exchange activity, expressed as H+ efflux (JH+)/min, and (B) cell proliferation in controls and PDGF-treated HSCs in the absence (vehicle) and presence of the PDGF-linked tyrosine kinase inhibitor tyrphostin A9. As evident, incubation with tyrphostin A9 significantly inhibited the stimulating effect of PDGF on both Na+/H+ exchange activity and HSC proliferation. *P < 0.01 and #P < vs. controls and tyrphostin A9.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

7. Fig. 6
(A) Na+/H+ exchange activity, expressed as H+ efflux (JH+)/min, in controls and PDGF-treated HSCs in the absence (vehicle) and presence of inhibitors of the PKC pathway (calphostin C), PI-3 kinase pathway (wortmannin), MAP kinase pathway (PD 98059), and PKA pathway (PKA inhibitory peptide). Only preincubation with calphostin C prevented PDGF-induced Na+/H+ exchange activation in HSCs. *P < 0.01 vs. controls and calphostin C. (B) HSC proliferation, expressed as percentage of BrdU-positive cells, in controls and in PDGF-treated HSCs in the absence (vehicle) and presence of inhibitors of the intracellular pathways cited above. As evident, preincubation with the PKA inhibitor did not modify PDGF-induced HSC proliferation, whereas preincubation with calphostin C, wortmannin, and PD significantly inhibited it. *P < vs. all other groups.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

8. Fig. 7
Correlation between maximal H+ efflux (JH+)/min and nadir pHi values in HSCs incubated for 24 hours with PDGF in the absence (vehicle) and presence of different intracellular pathway inhibitors. The intercept of the curve with y-axis represents the H+ efflux, whereas the intercept with x-axis represents the pHi set-point. The slope of the curve is a measure of the pHi dependence of pHi recovery. As clearly shown, both calphostin C and KN-62 reduced the y-axis intercept values as well as the slope of the regression lines, without affecting pHi set-point. On the contrary, neither wortmannin nor PD significantly modified y-axis intercept values and the slope of the regression lines in PDGF-treated HSCs.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

9. Fig. 8
(A) Na+/H+ exchange activity, expressed as H+ efflux (JH+)/min, and (B) cell proliferation in controls and in HSCs preincubated with PMA alone, with thapsigargin alone, or with both substances. As evident, only preincubation with both PMA and thapsigargin significantly increased both Na+/H+ exchange activity and HSC proliferation compared with controls. *P < 0.05 vs. PMA and thapsigargin; #P < vs. controls; ̂ P < 0.01 vs. other groups.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

10. Fig. 9
Proposed mechanism for PDGF-induced Na+/H+ exchange activation and proliferation in rat HSCs. R, receptor; TK, tyrosine kinase; DAG, diacylglycerol.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions