Protective Effects of Bisoprolol against Acute Exacerbation in Moderate-to-Severe Chronic Obstructive Pulmonary Disease

Although recent retrospective studies suggested that the use of β-blockers appears to help improve the mortality rate and decrease the rate of exacerbation in chronic obstructive pulmonary disease (COPD) patients with heart failure, the effects of β-blockers on COPD patients without heart failure have not been established. Based on previous reports, we have launched a multicenter, prospective, single-arm phase II study to evaluate the preventive effect of the cardioselective β-blocker bisoprolol in COPD exacerbation, in Japanese individuals with moderate-to-severe COPD who do not have heart failure but do have hypertension requiring the use of medication. The primary endpoint is the rate of mild-to-severe COPD exacerbation. The results of this study will clarify whether bisoprolol can prevent exacerbation in COPD patients without heart failure

Loss of IL-33 enhances elastase-induced and cigarette smoke extract-induced emphysema in mice

Background IL-33, which is known to induce type 2 immune responses via group 2 innate lymphoid cells, has been reported to contribute to neutrophilic airway inflammation in chronic obstructive pulmonary disease. However, its role in the pathogenesis of emphysema remains unclear. Methods We determined the role of interleukin (IL)-33 in the development of emphysema using porcine pancreas elastase (PPE) and cigarette smoke extract (CSE) in mice. First, IL-33(-/-) mice and wild-type (WT) mice were given PPE intratracheally. The numbers of inflammatory cells, and the levels of cytokines and chemokines in the bronchoalveolar lavage (BAL) fluid and lung homogenates, were analyzed; quantitative morphometry of lung sections was also performed. Second, mice received CSE by intratracheal instillation. Quantitative morphometry of lung sections was then performed again. Results Intratracheal instillation of PPE induced emphysematous changes and increased IL-33 levels in the lungs. Compared to WT mice, IL-33(-/-) mice showed significantly greater PPE-induced emphysematous changes. No differences were observed between IL-33(-/-) and WT mice in the numbers of macrophages or neutrophils in BAL fluid. The levels of hepatocyte growth factor were lower in the BAL fluid of PPE-treated IL-33(-/-) mice than WT mice. IL-33(-/-) mice also showed significantly greater emphysematous changes in the lungs, compared to WT mice, following intratracheal instillation of CSE. Conclusion These observations suggest that loss of IL-33 promotes the development of emphysema and may be potentially harmful to patients with COPD

Superiority of systemic bleomycin to intradermal HOCl for the study of interstitial lung disease

Abstract Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, immune dysregulation, and multi-organ fibrosis. Interstitial lung disease (ILD) is a complication of SSc and a leading cause of SSc-death. The administration of hypochlorous acid (HOCl) intradermally in the mouse (HOCl-SSc) purportedly shows several features typical of SSc. We studied the model by injecting BALB/c mice daily intradermally with HOCl for 6-weeks, an exposure reported to induce lung fibrosis. On day 42, the skinfold thickness and the dermal thickness were two and three times larger respectively in the HOCl group compared to controls. HOCl treatment did not result in histological features of pulmonary fibrosis nor significant changes in lung compliance. Automated image analysis of HOCl mice lungs stained with picrosirius red did not show increased collagen deposition. HOCl injections did not increase pulmonary mRNA expression of pro-fibrotic genes nor induced the production of serum advanced oxidation protein products and anti-topoisomerase 1 antibodies. Immune cells in bronchoalveolar lavage fluid (BALF) and whole lung digests were not increased in HOCl-treated animals. Since lung fibrosis is proposed to be triggered by oxidative stress, we injected HOCl to Nrf2−/− mice, a mouse deficient in many antioxidant proteins. Lung compliance, histology, and BALF leukocyte numbers were comparable between Nrf2−/− mice and wild-type controls. We conclude that the HOCl-SSc model does not manifest SSc-lung disease

A retinoid X receptor partial agonist attenuates pulmonary emphysema and airway inflammation

Abstract Background Retinoid X receptors (RXRs) are members of the nuclear receptor (NR) superfamily that mediate signalling by 9-cis retinoic acid, a vitamin A derivative. RXRs play key roles not only as homodimers but also as heterodimeric partners, e.g., for retinoic acid receptors, vitamin D receptors, and peroxisome proliferator-activated receptors. The NR family may also play important roles in the development of emphysema. However, the role of RXRs in the pathogenesis of emphysema is not well defined. Methods We developed a novel RXR partial agonist (NEt-4IB) and investigated its effect and mechanism compared to a full agonist (bexarotene) in a murine model of emphysema. For emphysema induction, BALB/c mice received intraperitoneal cigarette smoke extract (CSE) or intratracheal porcine pancreas elastase (PPE). Treatment with RXR agonists was initiated before or after emphysema induction. Results Treatment with NEt-4IB significantly suppressed the increase in static lung compliance and emphysematous changes in CSE-induced emphysema and PPE-induced established and progressive emphysema. NEt-4IB significantly suppressed PPE-induced neutrophilic airway inflammation and the levels of keratinocyte chemoattractant (KC), C-X-C motif ligand5 (CXCL5), interferon (IFN)-γ and IL-17. NEt-4IB also improved the matrix metalloproteinase-9 (MMP-9)/tissue inhibitor of metalloproteinase-1 (TIMP-1) imbalance and the reduced anti-oxidant activity in bronchoalveolar lavage (BAL) fluid. NEt-4IB suppressed PPE-induced vascular endothelial growth factor (VEGF) expression in the airway. Treatment with NEt-4IB and bexarotene significantly suppressed the increase in static lung compliance and emphysematous changes. However, adverse effects of RXR agonists, including hypertriglyceridemia and hepatomegaly, were observed in bexarotene-treated mice but not in NEt-4IB-treated mice. Conclusion These data suggest that RXRs play crucial roles in emphysema and airway inflammation, and novel partial RXR agonists could be potential therapeutic strategies for the treatment of PPE- and CSE-induced emphysema