Liver kinase B1 (LKB1) reduced inflammation and oxidative stress by regulating the AMPK/NLRP3 signaling pathway in LPS-induced lung injury

Yue Yifeng,Zong Liwu,Chen Yongmin,Nianhai Feng,Tang Junxia,Xu Hongyu,Zhao Meiling 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.4

Background Inflammation and oxidative stress-induced molecular death are one of the important causes for lung injury in critically ill patients. LKB1 is an important protein kinase in the body and has regulated inflammation and oxidative stress. However, LKB1 control inflammation and oxidative stress in lung injury were unclear. Objective We aimed to investigate the function and mechanism of Liver kinase B1 (LKB1) in lipopolysaccharide (LPS)-induced lung injury. Result LKB1 prevented lung injury, and weakened correlation oxidative stress and inflammatory reaction in LPS-induced mice model of lung injury. Up-regulation of LKB1 reduced reactive oxygen species (ROS) production and it-induced oxidative stress, and weakened inflammatory reactions in LPS-induced lung injury A549 cells. Down-regulation of LKB1 increased ROS production and it-induced oxidative stress, and enhanced inflammatory reactions in LPS-induced lung injury A549 cells. LKB1 induced phosphorylation (p)-AMPK protein expression, and suppressed the protein expression of NLRP3 in LPS-induced mice model of lung injury and in LPS-induced lung injury A549 cells. This experiment demonstrated the inhibition of AMPK or activation of NLRP3 inflammasome reversed the anti-inflammation function of LKB1 in LPS-induced lung injury. Meanwhile, ROS-induced oxidative stress also participated in the anti-inflammation effects of LKB1 in LPS-induced lung injury. Conclusion Therefore, our results indicate that LKB1 reduced inflammation and oxidative stress by regulating the AMPK/NLRP3 signaling pathway in LPS-induced lung injury.

Effects of Fdft 1 gene silencing and VD3 intervention on lung injury in hypoxia-stressed rats

Pu Xiaoyan,Lin Xue,Qi Yinglian,Li Yinglian,Li Tiantian,Liu Yang,Wei Dengbang 한국유전학회 2022 Genes & Genomics Vol.44 No.10

Background: Hypoxia can induce lung injury such as pulmonary arterial hypertension and pulmonary edema. And in the rat model of hypoxia-induced lung injury, the expression of Farnesyl diphosphate farnesyl transferase 1 (Fdft 1) was highly expressed and the steroid biosynthesis pathway was activated. However, the role of Fdft 1 and steroid biosynthesis pathway in hypoxia-induced lung injury remains unclear. Objective: The study aimed to further investigate the relationship between Fdft1 and steroid biosynthesis pathway with hypoxia-induced lung injury. Methods: A rat model of lung injury was constructed by hypobaric chamber with hypoxic stress, the adenovirus interference vector was used to silence the expression of Fdft 1, and the exogenous steroid biosynthesis metabolite Vitamin D3 (VD3) was used to treat acute hypoxia-induced lung injury in rats. Results: Sh-Fdft 1 and exogenous VD3 significantly inhibited the expression of Fdft 1 and the activation of the steroid pathway in hypoxia-induced lung injury rats, which showed a synergistic effect on the steroid activation pathway. In addition, sh-Fdft 1 promoted the increase of pulmonary artery pressure and lung water content, the decrease of oxygen partial pressure and oxygen saturation, and leaded to the increase of lung cell apoptosis and the aggravation of mitochondrial damage in hypoxia-stressed rats. And VD3 could significantly improve the lung injury induced by hypoxia and sh-Fdft 1 in rats. Conclusions: Fdft 1 gene silencing can promote hypoxic-induced lung injury, and exogenous supplement of VD3 has an antagonistic effect on lung injury induced by Fdft 1 gene silencing and hypoxic in rats, suggesting that VD3 has a preventive and protective effect on the occurrence and development of hypoxia-induced lung injury.

Inhibition of Phospholipase A<SUB>2</SUB> Diminishes the Acute Alveolar Injury Induced by Interleukin-1㄁

Young Man Lee 대한생리학회-대한약리학회 1997 The Korean Journal of Physiology & Pharmacology Vol.1 No.1

<P> In an attempt to investigate the role of phospholipase A<SUB>2</SUB>(PLA<SUB>2</SUB>) in interleukin-1 (IL-1) induced acute lung injury, mepacrine was tried to inhibit PLA<SUB>2</SUB> in IL-1 induced ARDS rats. For confirmation of acute lung injury by IL-1, and to know the role of neutrophils in this injury, lung leak index, lung myeloperoxidase(MPO), number of neutrophils and protein content in the bronchoalveolar lavage (BAL) and wet lung weight were measured. At the same time lung PLA<SUB>2</SUB> was measured to know the effect of IL-1 on PLA<SUB>2</SUB> activity. Pulmonary surfactant was also measured for an investigation of type II alveolar cell function. Neutrophil adhesion assay was performed to know the effect of PLA<SUB>2</SUB> inhibition <I>in vitro</I> with human umbilical vein endothelial cells (HUVEC). For precise location of injury by IL-1, morpholgical study was performed by electron microscopy. Five hours after instillation of IL-1 (50 ng/rat), lung leak index, protein content, number of neutrophils, lung MPO and wet lung weight were increased significantly. Five hours after IL-1 instillation lung PLA<SUB>2</SUB> activity was increased significantly, and increased surfactant release was observed in IL-1 induced ARDS rats BAL. In contrast, in rats given mepacrine and IL-1, there was decrease of acute lung injury i.e. decrease of lung leak index, wet lung weight, protein content, number of neutrophils in BAL and decreased lung MPO activity. Mepacrine decreased surfactant release also. Interestingly, inhibition of PLA<SUB>2 </SUB>decreased adhesion of human neutrophils to HUVEC <I>in vitro.</I> Morphologically, IL-1 caused diffuse necrosis of endothelial cells, type I and II epithelial cells and increased the infiltration of neutrophils in the interstitium of the lung but after mepacrine treatment these pathological findings were lessened. On the basis of these experimental results it is suggested that PLA<SUB>2</SUB> has a major role in the pathogenesis of acute lung injury mediated by neutrophil dependent manner in IL-1 induced acute lung injury.

Inhibition of Phospholipase $A_2$ Diminishes the Acute Alveolar Injury Induced by $Interleukin-1{\alpha}$

Lee, Young-Man The Korean Society of Pharmacology 1997 The Korean Journal of Physiology & Pharmacology Vol.1 No.1

In an attempt to investigate the role of phospholipase $A_2$($PLA_2$) in interleukin-l (IL-l) induced acute lung injury, mepacrine was tried to inhibit $PLA_2$ in IL-l induced ARDS rats. For confirmation of acute lung injury by IL-l, and to know the role of neutrophils in this injury, lung leak index, lung myeloperoxidase(MPO), number of neutrophils and protein content in the bronchoalveolar lavage (BAL) and wet lung weight were measured. At the same time lung $PLA_2$ was measured to know the effect of IL-l on $PLA_2$ activity. Pulmonary surfactant was also measured for an investigation of type II alveolar cell function. Neutrophil adhesion assay was performed to know the effect of $PLA_2$ inhibition in vitro with human umbilical vein endothelial cells (HUVEC). For precise location of injury by IL-l, morpholgical study was performed by electron microscopy. Five hours after instillation of IL-l (50 ng/rat), lung leak index, protein content, number of neutrophils, lung MPO and wet lung weight were increased significantly. Five hours after IL-l instillation lung $PLA_2$ activity was increased significantly, and increased surfactant release was observed in IL-l induced ARDS rats' BAL. In contrast, in rats given mepacrine and IL-l, there was decrease of acute lung injury i.e. decrease of lung leak index, wet lung weight, protein content, number of neutrophils in BAL and decreased lung MPO activity. Mepacrine decreased surfactant release also. Interestingly, inhibition of $PLA_2$ decreased adhesion of human neutrophils to HUVEC in vitro. Morphologically, IL-l caused diffuse necrosis of endothelial cells, type I and II epithelial cells and increased the infiltration of neutrophils in the interstitium of the lung but after mepacrine treatment these pathological findings were lessened. On the basis of these experimental results it is suggested that $PLA_2$ has a major role in the pathogenesis of acute lung injury mediated by neutrophil dependent manner in IL-l induced acute lung injury.

분만장에서의 미숙아 심폐소생술 시 비롯되는 미숙아 폐 손상의 기전 및 방어책

이현수 ( Hyeon Soo Lee ) 대한주산의학회 2010 Perinatology Vol.21 No.1

Neonatologists are deeply concerned with the concept of ventilator-induced lung injury (VILI) and they are greatly careful in the neonatal intensive care unit to apply positive-pressure ventilation (PPV) strategies that are gentle to the lungs. To achieve adequate gas exchange after delivery, lung fluid should be cleared and replaced with air, and functional residual capacity (FRC) should be established. However preterm newborns have difficulties establishing FRC and maintaining upper airway patency at birth. Hence majority of preterm newborns need some assistance to initiate breathing after birth and some require extensive resuscitation. PPV is therefore commonly used in the delivery room, however most clinicians including neonatologists or obstetricians appear less aware that the gentle approach as in NICU should be applied to prevent lung injury during the first few minutes of life. PPV may cause lung injury through various mechanisms such as high Vt (tidal volume) and overdistension (volutrauma), repeated alveolar collapse and re-expansion (atelect-trauma), and infection and inflammation (biotrauma), through which leads to epithelial cell injury, leakage of proteinaceous fluid into the lungs, inhibiting surfactant function and interfering lung mechanics, and consequently generating lung injury. In this review, I describe briefly what causes preterm lung injury during PPV based on animal and human researches, and I suggest some strategies to help minimize lung injury during resuscitation of preterm newborns in the delivery room.

Endotoxin-induced Acute Lung Injury is Mediated by PAF Produced via Remodelling of Lyso PAF in the Lungs

Young Man Lee,Teoan Kim 대한생리학회-대한약리학회 2000 The Korean Journal of Physiology & Pharmacology Vol.4 No.3

<P> In order to elucidate the role of platelet activating factor (PAF) in the acute lung injury induced by endotoxin (ETX), activities of phospholipase A2, lyso PAF acetyltransferase and oxidative stress by neutrophilic respiratory burst were probed in the present study. To induce acute lung injury, 100μg of <I>E.coli</I> ETX (type 0127; B8) was instilled directly into the tracheae of Sprague-Dawley rats. Five hours after the ETX instillation, induction of acute lung injury was confirmed by lung leak index and protein contents in the bronchoalveolar lavage (BAL) fluid. At the same time, lung phospholipase A2 (PLA2) activity and expression of group I and II secretory type PLA2 were examined. In these acutely injured rats, ketotifen fumarate, known as lyso PAF acetyltransferase inhibitor and mepacrine were administered to examine the role of PAF in the pathogenesis of the acute lung injury. To know the effect of the ETX in the synthesis of the PAF in the lungs, lyso PAF acetyltransferase activity and PAF content in the lungs were measured after treatments of ETX, ketotifen fumarate and mepacrine. In addition, the role of neutrophils causing the oxidative stress after ETX was examined by measuring lung myeloperoxidase (MPO) and enumerating neutrophils in the BAL fluid. To confirm the oxidative stress in the lungs, pulmonary contents of malondialdehyde (MDA) were measured. After instillation of the ETX in the lungs, lung leak index increased dramatically (p<0.001), whereas mepacrine and ketotifen decreased the lung leak index significantly (p<0.001). Lung PLA2 activity also increased (p<0.001) after ETX treatment compared with control, which was reversed by mepacrine and ketotifen (p<0.001). In the examination of expression of group I and II secretory PLA2, mRNA synthesis of the group II PLA2 was enhanced by ETX treatment, whereas ketotifen and WEB 2086, the PAF receptor antagonist, decreased the expression. The activity of the lysoPAF acetyltransferase increased (p<0.001) after treatment of ETX, which implies the increased synthesis of PAF by the remodelling of lysoPAF in the lungs. Consequently, the contents of the PAF in the lungs were increased by ETX compared with control (p<0.001), while mepacrine (p<0.001) and ketotifen (p<0.01) decreased the synthesis of the PAF in the lungs of ETX treated rats. The infiltration of the neutrophils was confirmed by measuring and enumerating lung MPO and the neutrophils in the BAL fluid respectively. Compared with control, ETX increased lung MPO and number of neutrophils in BAL significantly (p<0.001) whereas mepacrine and ketotifen decrerased number of neutrophils (p<0.001) and MPO (p<0.05, p<0.001, respectively). The lung MDA contents were also increased (p<0.001) by ETX treatment, but treatment with mepacrine (p<0.001) and ketotifen (p<0.01) decreased the lung MDA contents. Collectively, we conclude that ETX increases PLA2 activity, and that the subsequently increased production of PAF was ensued by the remodelling of the lyso PAF resulting in tissue injury by means of oxidative stress in the lungs.

Therapeutic potential of an indole derivative on murine models of environmental compound-associated lung injury

( Yong Chul Lee ),( Jae Seok Jeong ),( So Ri Kim ),( Hae Jin Park ),( Kyeong Hwa Park ),( Navin Ray ),( Yeong Hun Choe ),( Seung Yong Park ) 대한결핵 및 호흡기학회 2018 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.126 No.-

Various environmental compounds are implicated in fatal lung injury. Mitochondria are crucial organelles for normal lung function that can be impacted by many lung diseases. Recently, we developed an antioxidant indole-derived NecroX compound (NecroX), which preserves mitochondrial functionalities. In this study, we investigated therapeutic effects of NecroX on lung injury associated with polyhexamethylene guanidine (PHMG), a well-known chemical compound implicated in humidifier disinfectant- associated fatal lung injury in human, and bleomycin, a widely used chemical for inducing experimental lung fibrosis in mice, focusing on functionalities of mitochondria. Respiratory exposure to PHMG and bleomycin led to lung injury manifesting inflammation (increases of inflammatory cell infiltrations, TNF-α, IL-1β, IL-17, and KC) followed by fibrosis (elevated total collagen amount and TGF-β1) in the lung parenchyma, which was further verified by histopathologic and radiologic measurements. Exposure to these compounds impacted on mitochondria in regard to biogenesis, mitochondrial DNA (mtDNA) integrity, and generation of mitochondrial reactive oxygen species (mtROS) in various cells of the lung. Notably, NecroX significantly improved these pathobiologic features of the PHMG- and bleomycin-induced lung injury and ameliorated mitochondrial functionalities. These findings imply that NecroX has therapeutic potential in the treatment of environmental compound- induced lung injury.

흉부외상이 동반된 다발성 외상환자에서 폐손상 점수가 중환자실 치료에 미치는 영향

한국남 ( Kook Nam Han ),최석호 ( Seok Ho Choi ),김영철 ( Yeong Cheol Kim ),이경학 ( Kyoung Hak Lee ),이수언 ( Soo Eon Lee ),정기영 ( Ki Young Jeong ),서길준 ( Gil Joon Suh ) 대한외상학회 2011 大韓外傷學會誌 Vol.24 No.2

Purpose: Chest injuries in multiple trauma patients are major predisposing factor for increased length of stay in intensive care unit, prolonged mechanical ventilator, and respiratory complications such as pneumonia. The aim of this study is the evaluation of lung injury score as a risk factor for prolonged management in intensive care unit (ICU). Methods: Between June to August in 2011, 46 patients admitted to shock and trauma center in our hospital and 24 patients had associated chest damage without traumatic brain injury. Retrospectively, we calculated injury severity score (ISS), lung injury score, and the number of fractured ribs and performed nonparametric correlation analysis with length of stay in ICU and mechanical ventilator support. Results: Calculated lung injury score (<48 hours) was median 1(0-3) and ISS was median 30(8-38) in study population. They had median 2(0-14) fractured ribs. There were 2 bilateral fractures and 2 flail chest. Ventilator support was needed in 11(45.8%) of them for median 39 hours (6-166). The ISS of ventilator support group was median 34(24-34) and lung injury score was median 1.7(1.3-2.5). Tracheostomy was performed in one patient and it was only complicated case and ICU stay days was median 9(4-16). In correlation analysis, Lung injury score and ISS were significant with the length of stay in ICU but the number of fractured ribs and lung injury score were predicting factors for prolonged mechanical ventilator support. Conclusion: Lung injury score could be a possible prognostic factor for the prediction of increased length of stay in ICU and need for mechanical ventilator support.

Allylpyrocatechol ameliorates sepsis-induced lung injury via SIRT1-mediated suppression of p65 and nucleocytoplasmic translocation of HMGB1

Mu Yanfei,Mu Xiaosong,Yang Yan,Zhou Yanhong 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.4

Background Sepsis is a deadly clinical condition. Allylpyrocatechol is bioactive flavonoid that has shown promising anti-inflammatory and antioxidant activity. The effects of allylpyrocatechol on sepsis-induced lung injury have not been fully established. Objective This study investigated the effects of allylpyrocatechol in a mouse model of sepsis-induced lung injury. Results RAW264.7 macrophages were used for in vitro studies. A mouse model of sepsis was established by cecal ligation and puncture (CLP). The PaO2/FiO2 ratio was measured in conjunction with lung tissue histology, and edema was determined by the wet:dry tissue ratio. ELISA was performed to analyze levels of IL-6, TNF-α, NOx, and HMGB1. Malondialdehyde (MDA) levels were measured to determine lipid peroxidation status. Protein expression was investigated via Western blotting analyses. Molecular docking studies were done to study the affinity of SIRT1 with Allylpyrocatechol. It was observed that Allylpyrocatechol inhibited the production of HMGB1 and suppressed pro-inflammatory responses in macrophages treated with bacterial lipopolysaccharide (LPS) in vitro, and in CLP sepsis mice in vivo. Moreover, it ameliorated the reduction of SIRT1 levels in both LPS-treated macrophages and CLP mice, alleviated sepsis-induced lung edema, reduced lipid peroxidation, improved lung tissue histology findings, reduced mortality, and improved the PaO2/FiO2 ratio in CLP mice. Allylpyrocatechol caused significant reductions in serum levels of IL-6, nitric oxide, TNF-α, and HMGB1, as well as nuclear translocation of inducible nitric oxide synthase, SIRT1, and HMGB1 in lungs of CLP mice. Molecular docking analysis suggested affinity of SIRT1 with Allylpyrocatechol. Conclusion The findings suggest that Allylpyrocatechol protects mice against lung injury via SIRT1-mediated suppression of HMGB1 nuclear translocation and p-p65 activation. Background Sepsis is a deadly clinical condition. Allylpyrocatechol is bioactive flavonoid that has shown promising anti-inflammatory and antioxidant activity. The effects of allylpyrocatechol on sepsis-induced lung injury have not been fully established. Objective This study investigated the effects of allylpyrocatechol in a mouse model of sepsis-induced lung injury. Results RAW264.7 macrophages were used for in vitro studies. A mouse model of sepsis was established by cecal ligation and puncture (CLP). The PaO2/FiO2 ratio was measured in conjunction with lung tissue histology, and edema was determined by the wet:dry tissue ratio. ELISA was performed to analyze levels of IL-6, TNF-α, NOx, and HMGB1. Malondialdehyde (MDA) levels were measured to determine lipid peroxidation status. Protein expression was investigated via Western blotting analyses. Molecular docking studies were done to study the affinity of SIRT1 with Allylpyrocatechol. It was observed that Allylpyrocatechol inhibited the production of HMGB1 and suppressed pro-inflammatory responses in macrophages treated with bacterial lipopolysaccharide (LPS) in vitro, and in CLP sepsis mice in vivo. Moreover, it ameliorated the reduction of SIRT1 levels in both LPS-treated macrophages and CLP mice, alleviated sepsis-induced lung edema, reduced lipid peroxidation, improved lung tissue histology findings, reduced mortality, and improved the PaO2/FiO2 ratio in CLP mice. Allylpyrocatechol caused significant reductions in serum levels of IL-6, nitric oxide, TNF-α, and HMGB1, as well as nuclear translocation of inducible nitric oxide synthase, SIRT1, and HMGB1 in lungs of CLP mice. Molecular docking analysis suggested affinity of SIRT1 with Allylpyrocatechol. Conclusion The findings suggest that Allylpyrocatechol protects mice against lung injury via SIRT1-mediated suppression of HMGB1 nuclear translocation and p-p65 activation.

A Study on the Mechanism of Immunomodulating Effects of Moxifloxacin in Oleic Acid-Induced Acute Lung Injury

( Young Man Lee ) 대한결핵 및 호흡기학회 2011 Tuberculosis and Respiratory Diseases Vol.71 No.2

Background: It was hypothesized that the immunomodulating effects of moxifloxacin contribute to ameliorate oleic acid (OA)-induced acute lung injury (ALI) by suppression of cytosolic phospholipase A2 (cPLA2). This was based on observations from experiments on rats associated with neutrophilic respiratory burst, cPLA2 activity, and expressions of cPLA2, TNFα, and COX-II in the lung. Methods: ALI was induced by intravenous injection of OA in male Sprague-Dawley rats. Five hours after OA injection, protein content in bronchoalveolar lavage (BAL), lung myeloperoxidase (MPO) activity, and numbers of BAL neutrophils were measured. As an index of oxidative stress-induced lung injury, the content of malondialdehyde (MDA) in lung tissues was also determined. Lung histology, immunohistochemistry and determination of activity of cPLA2 in lung tissues were carried out. In addition, Western blotting of TNFα and COX-II in lung tissues was performed. Results: The accumulation of neutrophils in the lungs was observed after OA injection. BAL protein was increased along with neutrophilic infiltration and migration by OA. Moxifloxacin decreased all of these parameters of ALI and ameliorated ALI histologically. The increased malondialdehyde (MDA) in the lung by OA was also decreased by moxifloxacin. Moxifloxacin not only suppressed cPLA2 expression in the lungs and neutrophils but also decreased cPLA2 activity in lung tissues of rats given OA. The enhanced expressions of TNFα and COX-2 in the lung tissues of rats given OA were also suppressed by moxifloxacin. Conclusion: Moxifloxacin inhibited cPLA2 and down-regulated TNFα and COX-2 in the lungs of rats given OA, which resulted in the attenuation of inflammatory lung injury.