Figure 6: Etanercept reverses established pulmonary hypertension in the Sugen-hypoxia rat model.
Rats were given vehicle injections and maintained in normoxia (Control, n=6) or challenged with SU-5416 (20 mg kg−1, s.c.) and 3 weeks of hypoxia (10% O2) before 5 weeks of normoxia and 3 weeks of biweekly treatment with saline vehicle (S/H, n=9) or etanercept (S/H+Etan, n=9; 2.5 mg kg−1, i.p.). (a,b) Assessment of RVSP (a) and right ventricular hypertrophy (Fulton index (RV/LV+S)) (b). (c) Quantification of non-, partially and fully muscularized arteries as a percentage of total alveolar wall and duct arteries (n=6 for control, n=9 for all other groups; Student’s t-test for non-muscularized vessels). (d) BMPR2, ACVR2A and ALK2 mRNA expression, normalized to Actb, in lungs isolated from control, S/H and S/H+Etan rats (n=6). (e) Representative immunoblots of BMPR-II, phospho-Smad1/5, total Smad1, Notch2, Notch3, cleaved Caspase3, total Caspase3 and αSMA expression in lungs isolated from of control, S/H and S/H+Etan rats. Reprobed for β-actin to ensure equal loading (n=3). (f,g) Notch2 and Notch3 mRNA expression in lungs isolated from lungs of control, S/H and S/H+Etan rats. Expression was normalized to Actb (n=6). (h) Representative images of immunohistochemical staining for Notch2, Notch3 and αSMA in lung sections from control and S/H rats. Scale bars, 100 μm. One-way analysis of variance with post hoc Tukey’s for multiple comparisons used in a,b,d,f and g. */#P≤0.05, **/##P≤0.01, ***P≤0.001. Error bars represent mean±s.e.m.
