1.Liang-Ge-San Decoction Ameliorates Acute Respiratory Distress Syndrome via Suppressing p38MAPK-NF-κ B Signaling Pathway.
Quan LI ; Juan CHEN ; Meng-Meng WANG ; Li-Ping CAO ; Wei ZHANG ; Zhi-Zhou YANG ; Yi REN ; Jing FENG ; Xiao-Qin HAN ; Shi-Nan NIE ; Zhao-Rui SUN
Chinese journal of integrative medicine 2025;31(7):613-623
OBJECTIVE:
To explore the potential effects and mechanisms of Liang-Ge-San (LGS) for the treatment of acute respiratory distress syndrome (ARDS) through network pharmacology analysis and to verify LGS activity through biological experiments.
METHODS:
The key ingredients of LGS and related targets were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. ARDS-related targets were selected from GeneCards and DisGeNET databases. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed using the Metascape Database. Molecular docking analysis was used to confirm the binding affinity of the core compounds with key therapeutic targets. Finally, the effects of LGS on key signaling pathways and biological processes were determined by in vitro and in vivo experiments.
RESULTS:
A total of LGS-related targets and 496 ARDS-related targets were obtained from the databases. Network pharmacological analysis suggested that LGS could treat ARDS based on the following information: LGS ingredients luteolin, wogonin, and baicalein may be potential candidate agents. Mitogen-activated protein kinase 14 (MAPK14), recombinant V-Rel reticuloendotheliosis viral oncogene homolog A (RELA), and tumor necrosis factor alpha (TNF-α) may be potential therapeutic targets. Reactive oxygen species metabolic process and the apoptotic signaling pathway were the main biological processes. The p38MAPK/NF-κ B signaling pathway might be the key signaling pathway activated by LGS against ARDS. Moreover, molecular docking demonstrated that luteolin, wogonin, and baicalein had a good binding affinity with MAPK14, RELA, and TNF α. In vitro experiments, LGS inhibited the expression and entry of p38 and p65 into the nucleation in human bronchial epithelial cells (HBE) cells induced by LPS, inhibited the inflammatory response and oxidative stress response, and inhibited HBE cell apoptosis (P<0.05 or P<0.01). In vivo experiments, LGS improved lung injury caused by ligation and puncture, reduced inflammatory responses, and inhibited the activation of p38MAPK and p65 (P<0.05 or P<0.01).
CONCLUSION
LGS could reduce reactive oxygen species and inflammatory cytokine production by inhibiting p38MAPK/NF-κ B signaling pathway, thus reducing apoptosis and attenuating ARDS.
Drugs, Chinese Herbal/pharmacology*
;
Respiratory Distress Syndrome/enzymology*
;
p38 Mitogen-Activated Protein Kinases/metabolism*
;
NF-kappa B/metabolism*
;
Animals
;
Signal Transduction/drug effects*
;
Molecular Docking Simulation
;
Humans
;
Male
;
Network Pharmacology
;
Apoptosis/drug effects*
;
Mice
2.Quercetin Confers Protection against Sepsis-Related Acute Respiratory Distress Syndrome by Suppressing ROS/p38 MAPK Pathway.
Wei-Chao DING ; Juan CHEN ; Quan LI ; Yi REN ; Meng-Meng WANG ; Wei ZHANG ; Xiao-Hang JI ; Xin-Yao WU ; Shi-Nan NIE ; Chang-Bao HUANG ; Zhao-Rui SUN
Chinese journal of integrative medicine 2025;31(11):1011-1020
OBJECTIVE:
To identify the underlying mechanism by which quercetin (Que) alleviates sepsis-related acute respiratory distress syndrome (ARDS).
METHODS:
In vivo, C57BL/6 mice were assigned to sham, cecal ligation and puncture (CLP), and CLP+Que (50 mg/kg) groups (n=15 per group) by using a random number table. The sepsisrelated ARDS mouse model was established using the CLP method. In vitro, the murine alveolar macrophages (MH-S) cells were classified into control, lipopolysaccharide (LPS), LPS+Que (10 μmol/L), and LPS+Que+acetylcysteine (NAC, 5 mmol/L) groups. The effect of Que on oxidative stress, inflammation, and apoptosis in mice lungs and MH-S cells was determined, and the mechanism with reactive oxygen species (ROS)/p38 mitogen-activated protein kinase (MAPK) pathway was also explored both in vivo and in vitro.
RESULTS:
Que alleviated lung injury in mice, as reflected by a reversal of pulmonary histopathologic changes as well as a reduction in lung wet/dry weight ratio and neutrophil infiltration (P<0.05 or P<0.01). Additionally, Que improved the survival rate and relieved gas exchange impairment in mice (P<0.01). Que treatment also remarkedly reduced malondialdehyde formation, superoxide dismutase and catalase depletion, and cell apoptosis both in vivo and in vitro (P<0.05 or P<0.01). Moreover, Que treatment diminished the release of inflammatory factors interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 both in vivo and in vitro (P<0.05 or P<0.01). Mechanistic investigation clarifified that Que administration led to a decline in the phosphorylation of p38 MAPK in addition to the suppression of ROS expression (P<0.01). Furthermore, in LPS-induced MH-S cells, ROS inhibitor NAC further inhibited ROS/p38 MAPK pathway, as well as oxidative stress, inflammation, and cell apoptosis on the basis of Que treatment (P<0.05 or P<0.01).
CONCLUSION
Que was found to exert anti-oxidative, anti-inflammatory, and anti-apoptotic effects by suppressing the ROS/p38 MAPK pathway, thereby conferring protection for mice against sepsis-related ARDS.
Animals
;
Sepsis/drug therapy*
;
Quercetin/therapeutic use*
;
Respiratory Distress Syndrome/enzymology*
;
p38 Mitogen-Activated Protein Kinases/metabolism*
;
Mice, Inbred C57BL
;
Reactive Oxygen Species/metabolism*
;
Apoptosis/drug effects*
;
Male
;
Oxidative Stress/drug effects*
;
MAP Kinase Signaling System/drug effects*
;
Lung/drug effects*
;
Mice
;
Lipopolysaccharides
;
Macrophages, Alveolar/pathology*
;
Inflammation/pathology*
;
Protective Agents/therapeutic use*
3.Research progress on the relationship between mitochondrial dynamics imbalance and novel coronavirus infection-related acute respiratory distress syndrome.
Zijia ZHANG ; Bin DU ; Xunyao WU ; Xiaoyun HU ; Shitong DIAO ; Run DONG
Chinese Critical Care Medicine 2025;37(3):300-304
Patients with severe pneumonia caused by novel coronavirus infection are often complicated with acute respiratory distress syndrome (ARDS), which has a high mortality. ARDS is characterized by diffuse alveolar damage, pulmonary edema, and hypoxemia. Mitochondria are prone to morphological and functional abnormalities under hypoxia and viral infection, which can lead to cell apoptosis and damage, severely impacting the disease progression. Mitochondria maintain homeostasis through fission and fusion. In ARDS, hypoxia leads to the phosphorylation of dynamin-related protein 1 (Drp1), triggering excessive mitochondrial fission and damaging the alveolar epithelial barrier. Animal experiments have shown that inhibiting this process can alleviate lung injury, providing a potential direction for treatment. The pathology of novel coronavirus infection-related ARDS is similar to that of typical ARDS but more severe. Viral infection and hypoxia disrupt the mitochondrial balance, causing fission and autophagy abnormalities, promoting oxidative stress and mitochondrial DNA (mtDNA) release, activating inflammasomes, inducing the expression of hypoxia-inducible factor-1α (HIF-1α), exacerbating viral infection, inflammation, and coagulation reactions, and resulting in multiple organ damage. Mechanical ventilation and glucocorticoids are commonly used in the treatment of novel coronavirus infection-related ARDS. Mechanical ventilation is likely to cause lung and diaphragm injuries and changes in mitochondrial dynamics, while the lung protective ventilation strategy can reduce the adverse effects. Glucocorticoids can regulate mitochondrial function and immune response and improve the patient's condition through multiple pathways. The mitochondrial dynamics imbalance in novel coronavirus infection-related ARDS is caused by hypoxia and viral proteins, leading to lung and multiple organ injuries. To clarify the pathophysiological mechanism of mitochondrial dynamics imbalance in novel coronavirus infection-related ARDS and explore effective strategies for regulating mitochondrial dynamics balance to treat this disease, so as to provide new treatment targets and methods for patients with novel coronavirus infection-related ARDS. The existing treatments have limitations. Future research needs to deeply study the mechanism of mitochondrial dysfunction, develop new therapies and regulatory strategies, and improve the treatment effect.
Humans
;
Respiratory Distress Syndrome/etiology*
;
COVID-19
;
Mitochondrial Dynamics
;
Mitochondria/metabolism*
;
DNA, Mitochondrial
;
Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*
;
Dynamins
;
SARS-CoV-2
4.Relationship between blood glucose trajectory during intensive care unit stay and mortality in patients with sepsis-associated acute respiratory distress syndrome.
Yadi YANG ; Hanbing WANG ; Junzhu LIU ; Jingwen WU ; Li ZHOU ; Chunling JIANG
Chinese Critical Care Medicine 2025;37(10):924-930
OBJECTIVE:
To explore the association between blood glucose trajectories within 7 days of intensive care unit (ICU) admission and mortality in patients with sepsis-associated acute respiratory distress syndrome (ARDS).
METHODS:
Based on the MIMIC-IV database, sepsis-associated ARDS patients with daily blood glucose monitoring data within 7 days of ICU admission were selected. Blood glucose trajectories were analyzed using group-based trajectory modeling (GBTM), and the optimal number of groups was determined based on the minimum Akaike information criterion (AIC), Bayesian information criterion (BIC), average posterior probability (AvePP), odds of correct classification (OCC), and proportion of group membership (Prop). Baseline characteristics including demographics, comorbidities, severity scores, vital signs, laboratory indicators within the first 24 hours of ICU admission, and treatments were collected. Kaplan-Meier survival curves were used to compare 28-day and 1-year survival across trajectory groups. Multivariate Logistic regression was performed to evaluate the associations between glucose trajectory groups and in-hospital mortality, ICU mortality. The incidence of hypoglycemia within 7 days in the ICU was analyzed among different groups.
RESULTS:
A total of 3 869 patients with sepsis-associated ARDS were included, with a median age of 63.52 (52.13, 73.54) years; 59.6% (2 304/3 869) were male. Based on glucose levels within 7 days, patients were categorized into three groups: persistent hyperglycemia group (glucose maintained at 10.6-13.1 mmol/L, n = 894), moderate glucose group (7.8-8.9 mmol/L, n = 1 452), and low-normal glucose group (6.1-7.0 mmol/L, n = 1 523). There were statistically significant differences in 28-day mortality and 1-year mortality among low-normal glucose group, moderate glucose group, and persistent hyperglycemia group [28-day mortality: 11.42% (174/1 523), 19.83% (288/1 452), 25.50% (228/894), χ 2 = 82.545, P < 0.001; 1-year mortality: 23.31% (355/1 523), 33.75% (490/1 452), 39.49% (353/894), χ 2 = 77.376, P < 0.001]. Kaplan-Meier analysis showed that higher glucose trajectories were associated with significantly lower 28-day and 1-year cumulative survival rates (Log-rank test: χ 2 were 83.221 and 85.022, both P < 0.001). There were statistically significant differences in in-hospital mortality and ICU mortality among the low-normal glucose group, moderate glucose group, and persistent hyperglycemia group [in-hospital mortality: 9.65% (147/1 523), 19.70% (286/1 452), 24.50% (219/894), χ 2 = 102.020, P < 0.001; ICU mortality: 7.22% (110/1 523), 16.05% (233/1 452), 20.13% (180/894), χ 2 = 93.050, P < 0.001]. Logistic regression confirmed that, using the persistent hyperglycemia group as the reference, the low-normal glucose group had significantly lower risks of in-hospital mortality and ICU mortality after multiple factor adjustment. Although the moderate glucose group showed a trend toward lower mortality, the differences were not statistically significant. Using the moderate glucose group as a reference, the low-normal glucose group had 43.1% lower in-hospital mortality [odds ratio (OR) = 0.569, 95% confidence interval (95%CI) was 0.445-0.726, P < 0.001] and 42.0% lower ICU mortality (OR = 0.580, 95%CI was 0.439-0.762, P < 0.001). There was no statistically significant difference in the incidence of hypoglycemia within 7 days of ICU admission among low-normal glucose group, moderate glucose group, and persistent hyperglycemia group [2.82% (43/1 523), 2.69% (39/1 452), 3.02% (27/894), χ 2 = 0.226, P = 0.893].
CONCLUSIONS
Blood glucose trajectories during ICU stay are closely associated with prognosis in patients with sepsis-associated ARDS. Persistent hyperglycemia (10.6-13.1 mmol/L) is linked to significantly higher short- and long-term mortality.
Humans
;
Respiratory Distress Syndrome/etiology*
;
Sepsis/blood*
;
Intensive Care Units
;
Male
;
Female
;
Middle Aged
;
Blood Glucose/metabolism*
;
Hospital Mortality
;
Aged
5.Aspirin reduces lung inflammatory response in acute lung injury/acute respiratory distress syndrome: a Meta-analysis based on animal experiments.
Ying LIU ; Xianjun CHEN ; Chuan XIAO ; Jia YUAN ; Qing LI ; Lu LI ; Juan HE ; Feng SHEN
Chinese Critical Care Medicine 2024;36(12):1261-1267
OBJECTIVE:
To systematically evaluate the impact of aspirin on the pulmonary inflammatory response in animal models of acute lung injury/acute respiratory distress syndrome (ALI/ARDS).
METHODS:
Experimental research on aspirin therapy or prevention of ALI/ARDS in animal models were searched in PubMed, Web of Science, Cochrane library, Embase, China biology medicine, CNKI, Wanfang, VIP. The search time limit was from the establishment of the database to July 17, 2023. The control group established the ALI/ARDS model without any pharmacological intervention. The intervention group was given aspirin or aspirin-derived compounds or polymeric-aspirin (Poly-A) at different time points before and after the preparation of the model, of which there was no restriction on the dosage form, dosage, mode of administration, or number of doses. The primary outcome indicators included bronchoalveolar lavage fluid (BALF) or lung tissue myeloperoxidase (MPO) activity, interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α) and the counts of neutrophils in BALF. Two researchers screened the literature and extracted information based on inclusion and exclusion criteria. Literature quality was assessed by the bias risk assessment tool SYRCLE. RevMan 5.3 software was used for data synthesis and statistical analysis.
RESULTS:
A total of 17 papers were eventually included, involving a total of 449 animal models, all of which were murine. One paper was at high risk of bias and the rest 16 papers were at moderate risk of bias. Meta-analysis showed that compared with the control group, the neutrophil count in BALF [standardized mean difference (SMD) = -5.06, 95% confidence interval (95%CI) was -7.00 to -3.12, P < 0.000 01], the myeloperoxidase (MPO) activity in BALF or lung tissue (SMD = -3.45, 95%CI was -4.43 to -2.47, P < 0.000 01), the TNF-α level in BALF or lung tissue (SMD = -2.78, 95%CI was -3.58 to -1.98, P < 0.000 01), and the IL-1β level in BALF or lung tissue (SMD = -3.12, 95%CI was -4.56 to -1.69, P < 0.000 1) were significantly decreased in the ALI/ARDS model of the intervention group.
CONCLUSIONS
Aspirin reduces the level of lung inflammation in animal models of ALI/ARDS. However, there are problems of poor quality and significant heterogeneity of the included studies, which still need our further validation.
Animals
;
Acute Lung Injury/drug therapy*
;
Aspirin/pharmacology*
;
Respiratory Distress Syndrome/drug therapy*
;
Disease Models, Animal
;
Bronchoalveolar Lavage Fluid/chemistry*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Interleukin-1beta/metabolism*
;
Peroxidase/metabolism*
;
Lung/metabolism*
;
Neutrophils/drug effects*
6.Hepatocyte growth factor protects pulmonary endothelial barrier against oxidative stress and mitochondria-dependent apoptosis.
Shanshan MENG ; Feiping XIA ; Jingyuan XU ; Xiwen ZHANG ; Ming XUE ; Mingyuan GU ; Fengmei GUO ; Yingzi HUANG ; Haibo QIU ; Yi YANG
Chinese Medical Journal 2022;135(7):837-848
BACKGROUND:
Pulmonary microvascular endothelial cells (PMVECs) were not complex, and the endothelial barrier was destroyed in the pathogenesis progress of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Previous studies have demonstrated that hepatocyte growth factor (HGF), which was secreted by bone marrow mesenchymal stem cells, could decrease endothelial apoptosis. We investigated whether mTOR/STAT3 signaling acted in HGF protective effects against oxidative stress and mitochondria-dependent apoptosis in lipopolysaccharide (LPS)-induced endothelial barrier dysfunction and ALI mice.
METHODS:
In our current study, we introduced LPS-induced PMEVCs with HGF treatment. To investigate the effects of mammalian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT3) pathway in endothelial oxidative stress and mitochondria-dependent apoptosis, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 were, respectively, used to inhibit mTOR/STAT3 signaling. Moreover, lentivirus vector-mediated mTORC1 (Raptor) and mTORC2 (Rictor) gene knockdown modifications were introduced to evaluate mTORC1 and mTORC1 pathways. Calcium measurement, reactive oxygen species (ROS) production, mitochondrial membrane potential and protein, cell proliferation, apoptosis, and endothelial junction protein were detected to evaluate HGF effects. Moreover, we used the ALI mouse model to observe the mitochondria pathological changes with an electron microscope in vivo.
RESULTS:
Our study demonstrated that HGF protected the endothelium via the suppression of ROS production and intracellular calcium uptake, which lead to increased mitochondrial membrane potential (JC-1 and mitochondria tracker green detection) and specific proteins (complex I), raised anti-apoptosis Messenger Ribonucleic Acid level (B-cell lymphoma 2 and Bcl-xL), and increased endothelial junction proteins (VE-cadherin and occludin). Reversely, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 could raise oxidative stress and mitochondria-dependent apoptosis even with HGF treatment in LPS-induced endothelial cells. Similarly, mTORC1 as well as mTORC2 have the same protective effects in mitochondria damage and apoptosis. In in vivo experiments of ALI mouse, HGF also increased mitochondria structural integrity via the mTOR/STAT3 pathway.
CONCLUSION
In all, these reveal that mTOR/STAT3 signaling mediates the HGF suppression effects to oxidative level, mitochondria-dependent apoptosis, and endothelial junction protein in ARDS, contributing to the pulmonary endothelial survival and barrier integrity.
Animals
;
Apoptosis
;
Calcium/metabolism*
;
Endothelial Cells/metabolism*
;
Endothelium/metabolism*
;
Hepatocyte Growth Factor/metabolism*
;
Lipopolysaccharides/pharmacology*
;
Mammals/metabolism*
;
Mechanistic Target of Rapamycin Complex 1/metabolism*
;
Mechanistic Target of Rapamycin Complex 2/metabolism*
;
Mice
;
Mitochondria/metabolism*
;
Oxidative Stress
;
Reactive Oxygen Species/metabolism*
;
Respiratory Distress Syndrome
;
Sirolimus/pharmacology*
;
TOR Serine-Threonine Kinases/metabolism*
7.Role of extracellular vesicles in lung diseases.
Li ZHOU ; Hong LUO ; Jae Woo LEE
Chinese Medical Journal 2022;135(15):1765-1780
Extracellular vesicles (EVs) are anuclear particles composed of lipid bilayers that contain nucleic acids, proteins, lipids, and organelles. EVs act as an important mediator of cell-to-cell communication by transmitting biological signals or components, including lipids, proteins, messenger RNAs, DNA, microRNAs, organelles, etc, to nearby or distant target cells to activate and regulate the function and phenotype of target cells. Under physiological conditions, EVs play an essential role in maintaining the homeostasis of the pulmonary milieu but they can also be involved in promoting the pathogenesis and progression of various respiratory diseases including chronic obstructive pulmonary disease, asthma, acute lung injury/acute respiratory distress syndrome, idiopathic pulmonary fibrosis (IPF), and pulmonary artery hypertension. In addition, in multiple preclinical studies, EVs derived from mesenchymal stem cells (EVs) have shown promising therapeutic effects on reducing and repairing lung injuries. Furthermore, in recent years, researchers have explored different methods for modifying EVs or enhancing EVs-mediated drug delivery to produce more targeted and beneficial effects. This article will review the characteristics and biogenesis of EVs and their role in lung homeostasis and various acute and chronic lung diseases and the potential therapeutic application of EVs in the field of clinical medicine.
DNA/metabolism*
;
Extracellular Vesicles/metabolism*
;
Humans
;
Lipid Bilayers/metabolism*
;
Lung Diseases/therapy*
;
Lung Injury/metabolism*
;
MicroRNAs/metabolism*
;
Proteins/metabolism*
;
Respiratory Distress Syndrome
9.Mesenchymal stem cell therapy for acute respiratory distress syndrome: from basic to clinics.
Protein & Cell 2020;11(10):707-722
The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.
Adoptive Transfer
;
Alveolar Epithelial Cells
;
pathology
;
Animals
;
Apoptosis
;
Betacoronavirus
;
Body Fluids
;
metabolism
;
CD4-Positive T-Lymphocytes
;
immunology
;
Clinical Trials as Topic
;
Coinfection
;
prevention & control
;
therapy
;
Coronavirus Infections
;
complications
;
immunology
;
Disease Models, Animal
;
Endothelial Cells
;
pathology
;
Extracorporeal Membrane Oxygenation
;
Genetic Therapy
;
methods
;
Genetic Vectors
;
administration & dosage
;
therapeutic use
;
Humans
;
Immunity, Innate
;
Inflammation Mediators
;
metabolism
;
Lung
;
pathology
;
physiopathology
;
Mesenchymal Stem Cell Transplantation
;
methods
;
Mesenchymal Stem Cells
;
physiology
;
Multiple Organ Failure
;
etiology
;
prevention & control
;
Pandemics
;
Pneumonia, Viral
;
complications
;
immunology
;
Respiratory Distress Syndrome, Adult
;
immunology
;
pathology
;
therapy
;
Translational Medical Research
10.Effects of Hippo signaling pathway on lung injury repair by mesenchymal stem cells in acute respiratory distress syndrome.
Lang LI ; Liang DONG ; Fei GAO ; Jiaojie HUI ; Yizhe CHEN ; Jie YAN
Chinese Critical Care Medicine 2019;31(3):281-287
OBJECTIVE:
To investigate the effects of Hippo signaling pathway on lung injury repair of mesenchymal stem cells (MSC) in acute respiratory distress syndrome (ARDS) and its mechanism.
METHODS:
Mouse bone marrow-derived MSC (mMSCs) cell lines with low expression of large tumor suppressor 2 (LATS2) were constructed by lentiviral vector transfection. Male C57BL/6 mice aging 6-8 weeks old were divided into four groups according to random number table (n = 36). The ARDS animal model (ARDS group) was reproduced by intratracheally injection of 2 g/L lipopolysaccharide (LPS) 50 μL, the normal saline (NS) control group was injected with an equal volume of NS. After 4 hours of model reproduction, 5×104 mMSCs transfected with blank lentivirus vector (MSC-shcontrol group) or shLATS2 lentivirus vector (MSC-shLATS2 group) were transplanted intratracheally, while NS control group and ARDS group were injected with equal volume of phosphate buffered saline (PBS). Mice were sacrificed at 3, 7, and 14 days after modeling, and lung tissue and bronchoalveolar lavage fluid (BALF) were harvested. Near-infrared fluorescence imaging, immunofluorescence staining and Western Blot were used to track mMSCs in lung tissue. Retension and proportion of mMSC differentiation into type II alveolar epithelial cells (AEC II) were evaluated. Lung tissue wet weight/body weight ratio (LWW/BW) and total protein (TP) and albumin (ALB) in BALF were determined to reflect pulmonary edema. The expression of Occludin protein in lung epithelium was tested by Western Blot to reflect permeability of epithelium. The levels of interleukins (IL-1β, IL-6, IL-10) in BALF were assessed by enzyme-linked immunosorbent assay (ELISA) to reflect lung inflammation. Hematoxylin-eosin (HE) staining and modified Masson staining were carried out, and the scores were assessed to reflect lung injury and evaluate pulmonary fibrosis.
RESULTS:
The signal intensity of isolated lung fluorescence images at 3 days in the MSC-shLATS2 group was significantly higher than that in the MSC-shcontrol group (fluorescence intensity: 0.039±0.005 vs. 0.017±0.002, P < 0.05), the number of green fluorescent protein (GFP)-positive cells in lung tissue was also significantly higher than that in the MSC-shcontrol group (cells/HP: 29.65±6.98 vs. 17.50±4.58, P < 0.05), but they all decreased with time; and the proportion of mMSCs differentiated into AEC II was significantly increased [(64.12±15.29)% vs. (19.64±3.71)%, P < 0.05]. Compared with the NS control group, the levels of surface active protein C (SPC) and Occludin protein in the ARDS group were significantly decreased, LWW/BW ratio and TP, ALB and inflammatory factors levels in BALF were significantly increased; extensive alveolar and interstitial edema, hemorrhage and diffuse inflammatory cell infiltration were found in lung tissue, and the lung injury score was significantly increased; collagen fibers were deposited in alveolar septum and alveolar cavity, and pulmonary fibrosis score was also increased significantly. Compared with the ARDS group, the expression levels of SPC and Occludin at 14 days in the MSC-shcontrol group and the MSC-shLATS2 group were significantly increased (SPC/β-actin: 0.51±0.12, 0.68±0.10 vs. 0.27±0.08, Occludin/β-actin: 0.49±0.19, 0.79±0.11 vs. 0.25±0.08, all P < 0.05), TP, ALB, IL-1β, IL-6 levels in BALF at 3 days were significantly decreased [TP (g/L): 8.08±1.72, 5.12±0.87 vs. 12.55±2.09; ALB (g/L): 0.71±0.21, 0.44±0.18 vs. 1.18±0.29, IL-1β (ng/L): 99.26±14.32, 60.11±8.58 vs. 161.86±25.17, IL-6 (ng/L): 145.54±13.29, 101.74±11.55 vs. 258.79±27.88, all P < 0.05], and IL-10 was significantly increased (ng/L: 190.83±22.61, 316.65±37.88, both P < 0.05). Furthermore, all the above parameters in the MSC-shLATS2 group were significantly improved as compared with those in the MSC-shcontrol group (all P < 0.05). LWW/BW ratio in the MSC-shLATS2 group was significantly lower than that in the ARDS group and the MSC-shcontrol group (mg/g: 9.85±1.51 vs. 16.78±1.92, 14.88±1.74, both P < 0.05).
CONCLUSIONS
Inhibiting Hippo signaling pathway by low expression of LATS2 could promote the retention of mMSCs in lung tissue and differentiation into AEC II cells of ARDS mice, improve pulmonary edema and alveolar epithelial permeability, regulate pulmonary inflammatory response, and alleviate pathological damage and fibrosis of lung tissue.
Animals
;
Hippo Signaling Pathway
;
Lung Injury/prevention & control*
;
Male
;
Mesenchymal Stem Cells/metabolism*
;
Mice
;
Mice, Inbred C57BL
;
Protein Serine-Threonine Kinases/metabolism*
;
Respiratory Distress Syndrome/metabolism*
;
Signal Transduction

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