Immunology Letters 162 (2014) 18–26
Contents lists available at ScienceDirect
Immunology Letters journal homepage: www.elsevier.com/locate/immlet
Enforced expression of miR-125b attenuates LPS-induced acute lung injury Zhongliang Guo a,1 , Yutong Gu b,1 , Chunhong Wang c,1 , Jie Zhang a , Shan Shan c , Xia Gu c , Kailing Wang c , Yang Han d , Tao Ren c,∗ a
Department of VIP, East Hospital, Tongji University School of Medicine, Shanghai, China Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, China c Department of Respiratory Medicine, East Hospital, Tongji University School of Medicine, Shanghai, China d Department of Pathology, East Hospital, Tongji University School of Medicine, Shanghai, China b
a r t i c l e
i n f o
Article history: Received 9 March 2014 Received in revised form 11 June 2014 Accepted 15 June 2014 Available online 6 July 2014 Keywords: Acute respiratory distress syndrome Acute lung injury miR-125b
a b s t r a c t The acute respiratory distress syndrome (ARDS), a severe form of acute lung injury (ALI) in humans, is a leading cause of morbidity and mortality in critically ill patients. Despite decades of research, few therapeutic strategies for clinical ARDS have emerged. Recent evidence implicated a potential role of miR125b in development of ALI. Here we evaluated the miR-125b-based strategy in treatment of ARDS using the murine model of lipopolysaccharide (LPS)-induced ALI. We found that up-regulation of miR-125b expression maintained the body weight and survival of ALI mice, and significantly reduced LPS-induced pulmonary inflammation as reflected by reductions in total cell and neutrophil counts, proinflammatory cytokines, as well as chemokines in BAL fluid. Further, enforced expression of miR-125b resulted in remarkable reversal of LPS-induced increases in lung permeability as assessed by reductions in total protein, albumin and IgM in BAL fluid, and ameliorated the histopathology changes of lung in LPS-induced ALI mice. Of interest, serum miR-125b expression was also decreased and inversely correlated with the disease severity in patients with ARDS. Our findings strongly demonstrated that enforced expression of miR-125b could effectively ameliorate the LPS-induced ALI, suggesting a potential application for miR-125b-based therapy to treat clinical ARDS. © 2014 Elsevier B.V. All rights reserved.
1. Introduction Inflammatory lung disorders are characterized by increased leukocyte infiltration into lung tissues as the body’s immune response to infection or injury [1]. An important inflammatory lung disease of rapid onset is acute lung injury (ALI), which is a significant cause of morbidity and mortality in critically ill patients [1–5]. ALI is a diffuse, heterogeneous type of inflammatory lung disease clinically characterized by progressive hypoxemia, reduced lung compliance, and intense inflammation in the lung tissues [1,6]. The physiological hallmark of ALI is disruption of the alveolar–capillary membrane barrier, leading to development of noncardiogenic pulmonary edema, in which a proteinaceous exudate floods the alveolar spaces, impairs gas exchange, and precipitates respiratory failure [2,5–9]. ALI can result in persistent respiratory failure and
∗ Corresponding author. Tel.: +86 21 38804518x7217; fax: +86 21 58798999. E-mail address: [email protected] (T. Ren). 1 These authors contributed equally to this work. http://dx.doi.org/10.1016/j.imlet.2014.06.008 0165-2478/© 2014 Elsevier B.V. All rights reserved.
prolonged dependence on mechanical ventilation, increasing susceptibility to multiorgan dysfunction and mortality [9,10]. Despite extensive investigation aimed at early diagnostic and pathogenetic factors of ALI, current management is mainly supportive, as specific therapies have not been identified [5,9,11–15]. Therefore, new strategies are urgently required for achieving effective treatment of ALI, which might ultimately aid the clinical therapy for ARDS patients. MicroRNAs (miRNAs) have been shown to be centrally involved in the regulation of immune system development, differentiation of B and T cells, proliferation of monocytes and neutrophils, antibody production, release of inflammatory mediators and certain inflammatory lung diseases [1,16]. Recent study showed that miR125b, which could target the 3 -UTR of TNF-␣ and thus inhibit its expression, was down-regulated in macrophages in response to LPS stimulation in vitro, and was substantially decreased in spleens in C57BL/6 mice after injection with LPS [17]. Of interest, mice deficient in TNF-␣ or TNFR1 are resistant to LPS-induced shock whereas wild-type mice die within hours after LPS challenge, suggesting that the main cytokine responsible for this syndrome is TNF-␣ [17–19].
Z. Guo et al. / Immunology Letters 162 (2014) 18–26 Table 1 The clinical characters of ARDS patients. ARDS Demographics Male Female Age (years) Clinical parameters PaO2/FiO2 APACHE II SAPS II LIS Causes of ARDS Sepsis Lung contusion Shock
19
according to the ethical guidelines of the Tongji University Laboratory Animal Care and Use Committee. Number
2.3. Murine model of LPS-induced ALI 11 5 57.3 ± 13.7 176.50 ± 13.76 17.13 ± 3.48 39.19 ± 8.51 2.94 ± 0.23 12 1 3
(1) Shown as patient numbers or mean ± standard deviation values. (2) APACHE II, Acute Physiology and Chronic Health Evaluation (APACHE) II. SAPS II, Simplified Acute Physiology Score (SAPS) II. LIS, Murray Lung Injury Score (LIS).
These findings promoted us to hypothesize that enforced expression of miR-125b might be able to ameliorate the LPS-induced ALI. To test our hypothesis, here we carefully evaluate the potential role of miR-125b-based strategy in treatment of ALI using the murine model of LPS-induced ALI. We found that up-regulation of miR-125b significantly reduced LPS-induced pulmonary inflammation and resulted in remarkable reversal of LPS-induced increases in lung permeability, accompanied by a significant reduction of histopathology changes of lung. Our findings strongly demonstrated that enforced expression of miR-125b could effectively ameliorate the LPS-induced acute lung injury, suggesting a potential role for miR-125b-based therapy to treat patients with ARDS. 2. Materials and methods 2.1. Patients The human study was approved by the Ethics Committee of Tongji University. Sixteen patients with ARDS were enrolled and all the peripheral blood samples were collected from human subjects after obtaining informed consent. ARDS was defined as the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2)
Contents lists available at ScienceDirect
Immunology Letters journal homepage: www.elsevier.com/locate/immlet
Enforced expression of miR-125b attenuates LPS-induced acute lung injury Zhongliang Guo a,1 , Yutong Gu b,1 , Chunhong Wang c,1 , Jie Zhang a , Shan Shan c , Xia Gu c , Kailing Wang c , Yang Han d , Tao Ren c,∗ a
Department of VIP, East Hospital, Tongji University School of Medicine, Shanghai, China Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, China c Department of Respiratory Medicine, East Hospital, Tongji University School of Medicine, Shanghai, China d Department of Pathology, East Hospital, Tongji University School of Medicine, Shanghai, China b
a r t i c l e
i n f o
Article history: Received 9 March 2014 Received in revised form 11 June 2014 Accepted 15 June 2014 Available online 6 July 2014 Keywords: Acute respiratory distress syndrome Acute lung injury miR-125b
a b s t r a c t The acute respiratory distress syndrome (ARDS), a severe form of acute lung injury (ALI) in humans, is a leading cause of morbidity and mortality in critically ill patients. Despite decades of research, few therapeutic strategies for clinical ARDS have emerged. Recent evidence implicated a potential role of miR125b in development of ALI. Here we evaluated the miR-125b-based strategy in treatment of ARDS using the murine model of lipopolysaccharide (LPS)-induced ALI. We found that up-regulation of miR-125b expression maintained the body weight and survival of ALI mice, and significantly reduced LPS-induced pulmonary inflammation as reflected by reductions in total cell and neutrophil counts, proinflammatory cytokines, as well as chemokines in BAL fluid. Further, enforced expression of miR-125b resulted in remarkable reversal of LPS-induced increases in lung permeability as assessed by reductions in total protein, albumin and IgM in BAL fluid, and ameliorated the histopathology changes of lung in LPS-induced ALI mice. Of interest, serum miR-125b expression was also decreased and inversely correlated with the disease severity in patients with ARDS. Our findings strongly demonstrated that enforced expression of miR-125b could effectively ameliorate the LPS-induced ALI, suggesting a potential application for miR-125b-based therapy to treat clinical ARDS. © 2014 Elsevier B.V. All rights reserved.
1. Introduction Inflammatory lung disorders are characterized by increased leukocyte infiltration into lung tissues as the body’s immune response to infection or injury [1]. An important inflammatory lung disease of rapid onset is acute lung injury (ALI), which is a significant cause of morbidity and mortality in critically ill patients [1–5]. ALI is a diffuse, heterogeneous type of inflammatory lung disease clinically characterized by progressive hypoxemia, reduced lung compliance, and intense inflammation in the lung tissues [1,6]. The physiological hallmark of ALI is disruption of the alveolar–capillary membrane barrier, leading to development of noncardiogenic pulmonary edema, in which a proteinaceous exudate floods the alveolar spaces, impairs gas exchange, and precipitates respiratory failure [2,5–9]. ALI can result in persistent respiratory failure and
∗ Corresponding author. Tel.: +86 21 38804518x7217; fax: +86 21 58798999. E-mail address: [email protected] (T. Ren). 1 These authors contributed equally to this work. http://dx.doi.org/10.1016/j.imlet.2014.06.008 0165-2478/© 2014 Elsevier B.V. All rights reserved.
prolonged dependence on mechanical ventilation, increasing susceptibility to multiorgan dysfunction and mortality [9,10]. Despite extensive investigation aimed at early diagnostic and pathogenetic factors of ALI, current management is mainly supportive, as specific therapies have not been identified [5,9,11–15]. Therefore, new strategies are urgently required for achieving effective treatment of ALI, which might ultimately aid the clinical therapy for ARDS patients. MicroRNAs (miRNAs) have been shown to be centrally involved in the regulation of immune system development, differentiation of B and T cells, proliferation of monocytes and neutrophils, antibody production, release of inflammatory mediators and certain inflammatory lung diseases [1,16]. Recent study showed that miR125b, which could target the 3 -UTR of TNF-␣ and thus inhibit its expression, was down-regulated in macrophages in response to LPS stimulation in vitro, and was substantially decreased in spleens in C57BL/6 mice after injection with LPS [17]. Of interest, mice deficient in TNF-␣ or TNFR1 are resistant to LPS-induced shock whereas wild-type mice die within hours after LPS challenge, suggesting that the main cytokine responsible for this syndrome is TNF-␣ [17–19].
Z. Guo et al. / Immunology Letters 162 (2014) 18–26 Table 1 The clinical characters of ARDS patients. ARDS Demographics Male Female Age (years) Clinical parameters PaO2/FiO2 APACHE II SAPS II LIS Causes of ARDS Sepsis Lung contusion Shock
19
according to the ethical guidelines of the Tongji University Laboratory Animal Care and Use Committee. Number
2.3. Murine model of LPS-induced ALI 11 5 57.3 ± 13.7 176.50 ± 13.76 17.13 ± 3.48 39.19 ± 8.51 2.94 ± 0.23 12 1 3
(1) Shown as patient numbers or mean ± standard deviation values. (2) APACHE II, Acute Physiology and Chronic Health Evaluation (APACHE) II. SAPS II, Simplified Acute Physiology Score (SAPS) II. LIS, Murray Lung Injury Score (LIS).
These findings promoted us to hypothesize that enforced expression of miR-125b might be able to ameliorate the LPS-induced ALI. To test our hypothesis, here we carefully evaluate the potential role of miR-125b-based strategy in treatment of ALI using the murine model of LPS-induced ALI. We found that up-regulation of miR-125b significantly reduced LPS-induced pulmonary inflammation and resulted in remarkable reversal of LPS-induced increases in lung permeability, accompanied by a significant reduction of histopathology changes of lung. Our findings strongly demonstrated that enforced expression of miR-125b could effectively ameliorate the LPS-induced acute lung injury, suggesting a potential role for miR-125b-based therapy to treat patients with ARDS. 2. Materials and methods 2.1. Patients The human study was approved by the Ethics Committee of Tongji University. Sixteen patients with ARDS were enrolled and all the peripheral blood samples were collected from human subjects after obtaining informed consent. ARDS was defined as the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2)
