Enalapril protects mice from pulmonary hypertension by inhibiting TNF-mediated activation of NF-κB and AP-1

2002 ◽  
Vol 282 (6) ◽  
pp. L1209-L1221 ◽  
Author(s):  
Luis A. Ortiz ◽  
Hunter C. Champion ◽  
Joseph A. Lasky ◽  
Federica Gambelli ◽  
Evelyn Gozal ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Injury ◽  
Mrna Expression ◽  
Ace Inhibitor ◽  
Pulmonary Arterial ◽  
Factor Α ◽  
Deficient Mice ◽  
Enalapril Treatment ◽  
Necrosis Factor ◽  
Inhibitor Treatment

The present study was undertaken to investigate the effects of treatment with the angiotensin-converting enzyme (ACE) inhibitor enalapril in a mouse model of pulmonary hypertension induced by bleomycin. Bleomycin-induced lung injury in mice is mediated by enhanced tumor necrosis factor-α (TNF) expression in the lung, which determines the murine strain sensitivity to bleomycin, and murine strains are sensitive (C57BL/6) or resistant (BALB/c). Bleomycin induced significant pulmonary hypertension in C57BL/6, but not in BALB/c, mice; average pulmonary arterial pressure (PAP) was 26.4 ± 2.5 mmHg ( P < 0.05) vs. 15.2 ± 3 mmHg, respectively. Bleomycin treatment induced activation of nuclear factor (NF)-κB and activator protein (AP)-1 and enhanced collagen and TNF mRNA expression in the lung of C57BL/6 but not in BALB/c mice. Double TNF receptor-deficient mice (in a C57BL/6 background) that do not activate NF-κB or AP-1 in response to bleomycin did not develop bleomycin-induced pulmonary hypertension (PAP 14 ± 3 mmHg). Treatment of C57BL/6 mice with enalapril significantly ( P < 0.05) inhibited the development of pulmonary hypertension after bleomycin exposure. Enalapril treatment inhibited NF-κB and AP-1 activation, the enhanced TNF and collagen mRNA expression, and the deposition of collagen in bleomycin-exposed C57BL/6 mice. These results suggest that ACE inhibitor treatment decreases lung injury and the development of pulmonary hypertension in bleomycin-treated mice.

Cytokine treatment increases arginine metabolism and uptake in bovine pulmonary arterial endothelial cells

2001 ◽  
Vol 281 (5) ◽  
pp. L1232-L1239 ◽  
Author(s):  
Leif D. Nelin ◽  
Heather E. Nash ◽  
Louis G. Chicoine
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Cationic Amino Acid ◽  
Cytokine Treatment ◽  
Nitrite Production ◽  
Urea Production ◽  
Pulmonary Arterial ◽  
Factor Α ◽  
Arterial Endothelial Cells ◽  
Necrosis Factor

l-Arginine (l-Arg) is metabolized to nitric oxide (NO) by NO synthase (NOS) or to urea by arginase (AR). l-Arg is transported into bovine pulmonary arterial endothelial cells (BPAECs) by cationic amino acid transporter-2 (CAT-2). We hypothesized that cytokine treatment would increase l-Arg metabolism and increase CAT-2 mRNA expression. BPAECs were incubated for 24 h in medium (control) or medium with lipopolysaccharide and tumor necrosis factor-α (L-T). L-T increased nitrite production (3.1 ± 0.4 nmol/24 h vs. 1.8 ± 0.1 nmol/24 h for control; P< 0.01) and urea production (83.5 ± 29.5 nmol/24 h vs. 17.8 ± 8.6 nmol/24 h for control; P < 0.05). L-T-treated BPAECs had greater endothelial and inducible NOS mRNA expression compared with control cells. Increasing the medium l-Arg concentration resulted in increased nitrite and urea production in both the control and the L-T-treated BPAECs. L-T treatment resulted in measurable CAT-2 mRNA. L-T increasedl-[3H]Arg uptake (5.78 ± 0.41 pmol vs. 4.45 ± 0.10 pmol for control; P < 0.05). In summary, L-T treatment increased l-Arg metabolism to both NO and urea in BPAECs and resulted in increased levels of CAT-2 mRNA. This suggests that induction of NOS and/or AR is linked to induction of CAT-2 in BPAECs and may represent a mechanism for maintainingl-Arg availability to NOS and/or AR.

Arginase inhibition increases nitric oxide production in bovine pulmonary arterial endothelial cells

2004 ◽  
Vol 287 (1) ◽  
pp. L60-L68 ◽  
Author(s):  
Louis G. Chicoine ◽  
Michael L. Paffett ◽  
Tamara L. Young ◽  
Leif D. Nelin
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
No Synthase ◽  
No Production ◽  
Urea Production ◽  
Pulmonary Arterial ◽  
Factor Α ◽  
Arterial Endothelial Cells ◽  
Regular Medium ◽  
Necrosis Factor

Nitric oxide (NO) is produced by NO synthase (NOS) from l-arginine (l-Arg). Alternatively, l-Arg can be metabolized by arginase to produce l-ornithine and urea. Arginase (AR) exists in two isoforms, ARI and ARII. We hypothesized that inhibiting AR with l-valine (l-Val) would increase NO production in bovine pulmonary arterial endothelial cells (bPAEC). bPAEC were grown to confluence in either regular medium (EGM; control) or EGM with lipopolysaccharide and tumor necrosis factor-α (L/T) added. Treatment of bPAEC with L/T resulted in greater ARI protein expression and ARII mRNA expression than in control bPAEC. Addition of l-Val to the medium led to a concentration-dependent decrease in urea production and a concentration-dependent increase in NO production in both control and L/T-treated bPAEC. In a second set of experiments, control and L/T bPAEC were grown in EGM, EGM with 30 mM l-Val, EGM with 10 mM l-Arg, or EGM with both 10 mM l-Arg and 30 mM l-Val. In both control and L/T bPAEC, treatment with l-Val decreased urea production and increased NO production. Treatment with l-Arg increased both urea and NO production. The addition of the combination l-Arg and l-Val decreased urea production compared with the addition of l-Arg alone and increased NO production compared with l-Val alone. These data suggest that competition for intracellular l-Arg by AR may be involved in the regulation of NOS activity in control bPAEC and in response to L/T treatment.

Lung injury in a surfactant-deficient lung is modified by indomethacin

1990 ◽  
Vol 69 (6) ◽  
pp. 2067-2071 ◽  
Author(s):  
R. Burger ◽  
D. Fung ◽  
A. C. Bryan
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Injury ◽  
Thromboxane A2 ◽  
Neutrophil Infiltration ◽  
Lung Lavage ◽  
Thromboxane A2 Receptor ◽  
Beneficial Effects ◽  
Thromboxane Receptor ◽  
Pulmonary Arterial ◽  
Arterial Po2

Repetitive total lung lavage in adult rabbits leads to a reproducible severe surfactant-deficient lung injury. Hypoxemia requiring mechanical ventilation occurs, accompanied by a substantial pulmonary hypertension, a large intra-alveolar protein leak, peripheral neutropenia, and pathological features of marked neutrophil infiltration with extensive hyaline membrane formation. Pretreatment with indomethacin abolishes postlavage pulmonary hypertension, preserves a slightly better lung function with higher arterial PO2, and prevents the postlavage peripheral neutropenia found in untreated animals. Pretreatment with a thromboxane A2 receptor blocker (L 655,240, Merck Frosst, Canada) also completely attenuated pulmonary hypertension, providing evidence that thromboxane A2 mediates pulmonary arterial hypertension after lung lavage. However, specific thromboxane receptor blockade had no other long-lasting beneficial effects on the ongoing injury in this model.

Locally Produced Tumor Necrosis Factor-α Mediates Interleukin-2Induced Lung Injury

1996 ◽  
Vol 78 (2) ◽  
pp. 329-336 ◽  
Author(s):  
R. Rabinovici ◽  
G. Feuerstein ◽  
F. Abdullah ◽  
M. Whiteford ◽  
P. Borboroglu ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Lung Injury ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Factor Α ◽  
Necrosis Factor

scholarly journals Exacerbated Imiquimod-Induced Psoriasis-Like Skin Inflammation in IRF5-Deficient Mice

2020 ◽  
Vol 21 (10) ◽  
pp. 3681
Author(s):  
Momoko Nakao ◽  
Tomomitsu Miyagaki ◽  
Makoto Sugaya ◽  
Shinichi Sato
Keyword(s):  
Critical Role ◽  
Skin Inflammation ◽  
Interferon Α ◽  
Toll Like Receptor ◽  
Adaptive Immune ◽  
Th17 Cytokines ◽  
Factor Α ◽  
Deficient Mice ◽  
Necrosis Factor

Interferon regulatory factors (IRFs) play diverse roles in the regulation of the innate and adaptive immune responses in various diseases. In psoriasis, IRF2 is known to be involved in pathogenesis, while studies on other IRFs are limited. In this study, we investigated the role of IRF5 in psoriasis using imiquimod-induced psoriasis-like dermatitis. Although IRF5 is known to play a critical role in the induction of proinflammatory cytokines by immune cells, such as dendritic cells (DCs), macrophages, and monocytes, IRF5 deficiency unexpectedly exacerbated psoriasiform skin inflammation. The interferon-α and tumor necrosis factor-α mRNA expression levels were decreased, while levels of Th17 cytokines including IL-17, IL-22, and IL-23 were increased in IRF5-deficient mice. Furthermore, IL-23 expression in DCs from IRF5-deficient mice was upregulated both in steady state and after toll-like receptor 7/8 agonist stimulation. Importantly, the expression of IRF4, which is also important for the IL-23 production in DCs, was augmented in DCs from IRF5-deficient mice. Taken together, our results suggest that IRF5 deficiency induces the upregulation of IRF4 in DCs followed by augmented IL-23 production, resulting in the amplification of Th17 responses and the exacerbation of imiquimod-induced psoriasis-like skin inflammation. The regulation of IRF4 or IRF5 expression may be a novel therapeutic approach to psoriasis.

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