Fig. 9.

Primary isolated murine pulmonary microvascular endothelial cells (PMVECs) with endothelial HIF deletion have decreased monolayer permeability and increased potassium channel (Kv1.5) expression. A: by quantitative PCR on cell lysates, PMVECs from endothelial HIF-targeted mice had an increase in Kv1.5 channel mRNA expression in response to hypoxia compared with controls. B: PMVECs from endothelial HIF-targeted mice had an increased transcellular resistance as measured by TEER after exposure to hypoxia (O₂ 1%) for 24 h, compared with control cells under normoxic condition. C: relative intracellular calcium concentration, as measured by fura-2 AM, was decreased in HIF1/2 KO PMVECs compared with control, upon exposure to 24 h of hypoxia (O₂ 1%). For all experiments; n = 3 per group. D: representative vascular leak images, as measured by Angiosense tissue permeability, of control and endothelial HIF1/2 KO mice exposed to vehicle vs. intraperitoneal bleomycin for 2 wk. Head to the left and tail to the right of each image. Green color is indicative of vascular leak and is greatest over the chest and normalized to bladder. E: by quantitation of individual images, and normalized leak intensity (corresponding to increased pulmonary permeability) was greater in control vs. endothelial HIF1/2 KO mice, exposed to bleomycin. n = 6 per group, *P < 0.05.