Inflammation and ischemia-induced lung angiogenesis

Abstract

A role for inflammation in modulating the extent of angiogenesis has been shown for a number of organs. The present study was undertaken to evaluate the importance of leukocyte subpopulations for systemic angiogenesis of the lung after left pulmonary artery ligation (LPAL) in a mouse model of chronic pulmonary thromboembolism. Since we (24) previously showed that depletion of neutrophils did not alter the angiogenic outcome, we focused on the effects of dexamethasone pretreatment (general anti-inflammatory) and gadolinium chloride treatment (macrophage inactivator) and studied Rag-1(-/-) mice (T/B lymphocyte deficient). We measured inflammatory cells in bronchoalveolar lavage fluid and lung homogenate macrophage inflammatory protein-2 (MIP-2) and IL-6 protein levels within 24 h after LPAL and systemic blood flow to the lung 14 days after LPAL with labeled microspheres as a measure of angiogenesis. Blood flow to the left lung was significantly reduced after dexamethasone treatment compared with untreated control LPAL mice (66% decrease; P < 0.05) and significantly increased in T/B lymphocyte-deficient mice (88% increase; P < 0.05). Adoptive transfer of splenocytes (T/B lymphocytes) significantly reversed the degree of angiogenesis observed in the Rag-1(-/-) mice back to the level of control LPAL. Average number of lavaged macrophages for each group significantly correlated with average blood flow in the study groups (r(2) = 0.9181; P = 0.01 different from 0). Despite differences in angiogenesis, left lung homogenate MIP-2 and IL-6 did not differ among study groups. We conclude that inflammatory cells modulate the degree of angiogenesis in this lung model where lymphocytes appear to limit the degree of neovascularization, whereas monocytes/macrophages likely promote angiogenesis.

Differential activity of pro-angiogenic CXC chemokines

“…Male mice (C57Bl/6, 5–6 weeks; Charles River Wilmington, MA) were studied as previously described (McClintock and Wagner, 2005; Wagner et al, 2008). Mice were anesthetized (2% isoflurane), intubated and ventilated (120 breaths/min, 0.2 ml/breath).…”

In vitro and in vivo evaluation of a novel nanosize hydroxyapatite particles/poly(ester-urethane) composite scaffold for bone tissue engineering

“…size, shape, surface chemistry) [8,9]. Inflammation, in turn, is closely linked to the process of angiogenesis [10], which is necessary for the adequate vascularization of scaffolds after implantation into the host tissue.…”

A Deficiency in the Prostaglandin D2 Receptor CRTH2 Exacerbates Adjuvant-Induced Joint Inflammation

“…To decrease macrophage number and activity in an in vivo situation (34), GdCl 3 (100 mg/kg) was administered i.p. 1 d prior to CFA treatment and, subsequently, on alternating days.…”