1.Risk factors and prognosis of first extubation failure in neonates undergoing invasive mechanical ventilation.
Mengyao WU ; Hui RONG ; Rui CHENG ; Yang YANG ; Keyu LU ; Fei SHEN
Journal of Central South University(Medical Sciences) 2025;50(8):1398-1407
OBJECTIVES:
Prolonged invasive mechanical ventilation is associated with increased risks of severe complications such as retinopathy of prematurity and bronchopulmonary dysplasia. Although neonatal intensive care unit (NICU) follow the principle of early extubation, extubation failure rates remain high, and reintubation may further increase the risk of adverse outcomes. This study aims to identify risk factors and short-term prognosis associated with first extubation failure in neonates, to provide evidence for effective clinical intervention strategies.
METHODS:
Clinical data of neonates who received invasive ventilation in the NICU of Children's Hospital of Nanjing Medical University from January 1, 2019, to December 31, 2021, were retrospectively collected. Neonates were divided into a successful extubation group and a failed extubation group based on whether reintubation occurred within 72 hours after the first extubation. Risk factors and short-term outcomes related to extubation failure were analyzed.
RESULTS:
A total of 337 infants were included, with 218 males (64.69%). Initial extubation failed in 34 (10.09%) infants. Compared with the successful extubation group, the failed extubation group had significantly lower gestational age [(31.37±5.14) weeks vs (34.44±4.07) weeks], age [2.5 (1.00, 8.25) h vs 5 (1.00, 22.00) h], birth weight [(1 818.97±1128.80) g vs (2 432.18±928.94) g], 1-minute Apgar score (6.91±1.90 vs 7.68±2.03), and the proportion of using mask oxygenation after extubation (21% vs 46%) (all P<0.05). Conversely, compared with the successful extubation group, the failed extubation group had significantly higher rates of vaginal delivery (59% vs 32%), caffeine use during mechanical ventilation (71% vs 38%), dexamethasone use at extubation (44% vs 17%), the highest positive end-expiratory pressure level within 72 hours post-extubation [6(5.00, 6.00) cmH2O vs 5 (0.00, 6.00) cmH2O] (1 cmH2O=0.098 kPa), the highest FiO2 within 72 hours post-extubation [(34.35±5.95)% vs (30.22±3.58)%], and duration of noninvasive intermittent positive pressure ventilation after extubation [0.5 (0.00, 42.00) hours vs 0 (0, 0) hours] (all P<0.05). Multivariate analysis identified gestational age <28 weeks (OR=5.570, 95% CI 1.866 to 16.430), age at NICU admission (OR=0.959, 95% CI 0.918 to 0.989), and a maximum FiO2≥35% within 72 hours post-extubation (OR=4.541, 95% CI 1.849 to 10.980) as independent risk factors for extubation failure (all P<0.05). Additionally, the failed extubation group exhibited significantly higher incidences of necrotizing enterocolitis grade II or above, moderate-to-severe bronchopulmonary dysplasia, severe bronchopulmonary dysplasia, retinopathy of prematurity, treatment abandonment due to poor prognosis, and discharge on home oxygen therapy (all P<0.05). Total hospital length of stay and total hospitalization costs were also significantly increased in the failed extubation group (all P<0.05).
CONCLUSIONS
Gestational age <28 weeks, younger age at NICU admission, and FiO2≥35% after extubation are high-risk factors for first extubation failure in neonates. Extubation failure markedly increases the risk of adverse clinical outcomes.
Humans
;
Infant, Newborn
;
Male
;
Female
;
Airway Extubation/adverse effects*
;
Risk Factors
;
Retrospective Studies
;
Respiration, Artificial/methods*
;
Intensive Care Units, Neonatal
;
Prognosis
;
Gestational Age
;
Bronchopulmonary Dysplasia
;
Infant, Premature
;
Treatment Failure
;
Intubation, Intratracheal
2.Research progress on the role of mechanical stretch in the injury and repair of alveolar epithelial cells.
Xinyi TANG ; Haoyue XUE ; Yongpeng XIE
Chinese Critical Care Medicine 2025;37(1):92-96
Mechanical ventilation (MV) is currently widely used in the treatment of respiratory failure and anesthesia surgery, and is a commonly used respiratory support method for critically ill patients; however, improper usage of MV can lead to ventilator-induced lung injury (VILI), which poses a significant threat to patient life. Alveolar epithelial cell (AEC) has the functions of mechanosensation and mechanotransduction. Physiological mechanical stretching is beneficial for maintaining the lineage homeostasis and normal physiological functions of AEC cells, while excessive mechanical stretching can cause damage to AEC cells. Damage to AEC cells is an important aspect in the occurrence and development of VILI. Understanding the effects of mechanical stretching on AEC cells is crucial for developing safe and effective MV strategies, preventing the occurrence of VILI, and improving the clinical prognosis of VILI patients. From the perspective of cell mechanics, this paper aims to briefly elucidate the mechanical properties of AEC cells, mechanosensation and mechanotransduction of mechanical stretching in AEC cells, and the injury and repair of AEC cells under mechanical stretch stimulation, and potential mechanisms with the goal of helping clinical doctors better understand the pathophysiological mechanism of VILI caused by MV, improve their understanding of VILI, provide safer and more effective strategies for the use of clinical MV, and provide theoretical basis for the prevention and treatment of VILI.
Humans
;
Mechanotransduction, Cellular
;
Ventilator-Induced Lung Injury
;
Stress, Mechanical
;
Alveolar Epithelial Cells
;
Respiration, Artificial/adverse effects*
;
Epithelial Cells
;
Pulmonary Alveoli/cytology*
;
Animals
3.Research advancements on the role of long non-coding RNA in ventilator-induced lung injury.
Zhijiang FU ; Leilei ZHOU ; Xianming ZHANG
Chinese Critical Care Medicine 2025;37(2):188-192
Mechanical ventilation is commonly employed for respiratory support in patients with respiratory failure. Despite the optimization of ventilator parameters and treatment methods, mechanical ventilation can still lead to both acute and chronic lung injury in patients with acute respiratory distress syndrome (ARDS) as well as in those without ARDS, a phenomenon referred to as ventilator-induced lung injury (VILI). VILI can be categorized into four types: barotrauma, volumetric injury, atelectasis injury, and biotic injury. Among these, biotic injury, characterized by inflammation, plays a significant role in the pathogenesis of VILI. Numerous studies have investigated the inflammatory mechanisms underlying VILI; however, these mechanisms remain complex and not entirely understood. At present, clinical practice lacks specific prevention and treatment strategies for VILI, aside from the implementation of protective ventilation strategies. Long non-coding RNAs (lncRNA) are a category of non-coding RNA longer than 200 nucleotides. LncRNAs regulate physiological and pathological processes such as cell proliferation, apoptosis, inflammatory response, and immune regulation, this regulation occurs through mechanisms such as modulating gene activity, inhibiting specific states, assisting in transcription initiation, affecting pre-mRNA splicing modifications, influencing translation processes, and expressing biofunctional peptides. They play an important role in the course of multiple diseases. Studies have shown that compared with control animals and cell models, lncRNAs are differentially expressed in VILI animal models and cell stretch models. Experiments have verified that certain lncRNAs play a crucial role in the pathogenesis of VILI by regulating the expression of inflammatory factors, the transformation of macrophage types, neutrophil activation, and cell apoptosis. Given the adverse effects of VILI on mechanical ventilation in critically ill patients, the important role of lncRNAs in biological regulation, and the urgent need to explore more effective strategies for the prevention and treatment of VILI, this paper summarizes the mechanisms through which lncRNA contributes to the VILI process, and discusses its possibility as a diagnostic and therapeutic target of VILI, in order to provide a reference for the clinical treatment of VILI.
RNA, Long Noncoding
;
Ventilator-Induced Lung Injury
;
Humans
;
Respiration, Artificial/adverse effects*
;
Animals
;
Respiratory Distress Syndrome
;
Apoptosis
4.Effect of transcutaneous phrenic nerve stimulation in preventing ventilator-induced diaphragmatic dysfunction in invasive mechanically ventilated patients.
Yuhua SHEN ; Hongyan ZHANG ; Lingyan WANG ; Xianbin SONG ; Xianjiang WANG ; Aili CAO
Chinese Critical Care Medicine 2025;37(4):343-347
OBJECTIVE:
To explore the preventive effect of transcutaneous phrenic nerve stimulation on ventilator-induced diaphragmatic dysfunction (VIDD) in patients requiring invasive mechanical ventilation.
METHODS:
A randomized controlled trial was conducted. The patients requiring invasive mechanical ventilation admitted to the intensive care unit (ICU) of Jiaxing First Hospital from November 2022 to December 2023 were enrolled. Participants were randomized into the control group and the observation group using a random number table. The control group was given ICU standardized nursing intervention, including turning over and slapping the back, raising the head of the bed, sputum aspiration on demand, aerosol inhalation, oral care, and monitoring of airbag pressure and gastric retention, the observation group was given additional transcutaneous phrenic nerve stimulation intervention on the basis of ICU standardized nursing intervention. The stimulation intensity was set to 10 U, the pulse frequency was set to 40 Hz, and the stimulation frequency was set to 12 times/min. Transcutaneous phrenic nerve stimulation was administered once a day for 30 minutes each time, for a total of 5 days. Diaphragm thickening fraction (DTF) and arterial blood gas parameters on days 1, 3, and 5 of intervention were compared between the two groups. After 5 days of intervention, other parameters including the incidence of VIDD, duration of mechanical ventilation, and length of ICU stay were compared.
RESULTS:
A total of 120 patients requiring invasive mechanical ventilation were enrolled, with 16 dropouts (dropout rate was 13.33%). Ultimately, 51 patients in the control group and 53 patients in the observation group were analyzed. Baseline characteristics, including gender, age, body mass index (BMI), acute physiology and chronic health evaluation II (APACHE II) score, albumin (Alb), hemoglobin (Hb), and disease type, showed no significant differences between the two groups. DTF in both groups gradually increased over duration of intervention [DTF on days 1, 3, and 5 in the control group was (20.83±2.33)%, (21.92±1.27)%, and (23.93±2.33)%, respectively, and that in the observation group was (20.89±1.96)%, (22.56±1.64)%, and (25.34±2.38)%, respectively], with more significant changes in DTF in the observation group, showing time effects (Ftime = 105.975, P < 0.001), intervention effects (Fintervention = 7.378, P = 0.008), and interaction effects (Finteraction = 3.322, P = 0.038). Arterial blood gas parameters did not differ significantly before intervention between the groups, but after 5 days of intervention, arterial partial pressure of oxygen (PaO2) in the observation group was significantly higher than that in the control group [mmHg (1 mmHg≈0.133 kPa): 100.72±15.75 vs. 93.62±15.54, P < 0.05], and arterial partial pressure of carbon dioxide (PaCO2) was significantly lower than that in the control group (mmHg: 36.53±3.10 vs. 37.69±2.02, P < 0.05). At 5 days of intervention, the incidence of VIDD in the observation group was significantly lower than that in the control group [15.09% (8/53) vs. 37.25% (19/51), P < 0.05], and both duration of mechanical ventilation and length of ICU stay were significantly shorter than those in the control group [duration of mechanical ventilation (days): 7.93±2.06 vs. 8.77±1.76, length of ICU stay (days): 9.64±2.35 vs. 11.01±2.01, both P < 0.05].
CONCLUSIONS
Transcutaneous phrenic nerve stimulation can improve diaphragmatic and respiratory function in patients receiving invasive mechanical ventilation, reduce the incidence of VIDD, and shorten the duration of mechanical ventilation and length of ICU stay.
Humans
;
Transcutaneous Electric Nerve Stimulation
;
Respiration, Artificial/adverse effects*
;
Diaphragm/physiopathology*
;
Phrenic Nerve
;
Intensive Care Units
;
Male
;
Female
;
Middle Aged
5.Analysis of the current status and influencing factors of enteral nutrition intolerance in intensive care unit patients.
Zhu ZHU ; Piao LEI ; Junyun HUO ; Tao LI ; Huan YAO
Chinese Critical Care Medicine 2024;36(12):1296-1300
OBJECTIVE:
To investigate the current status and influencing factors of feeding intolerance (FI) during enteral nutrition (EN) in intensive care unit (ICU) patients.
METHODS:
A retrospective case-control study was conducted, including patients from two ICU wards of a tertiary hospital in Guizhou Province from July 2019 to December 2022. Clinical data were collected using a self-designed data collection form, including general information [age, gender, acute physiology and chronic health evaluation II (APACHE II)], clinical treatment (mechanical ventilation, mild hypothermia therapy), medication use (vasoactive drugs, glucocorticoids, analgesics, sedatives), EN implementation (types of EN fluids, EN methods, tube feeding rate), EN tolerance, and blood glucose status. Patients were divided into EN tolerance and EN intolerance groups based on the FI criteria. Differences in the above-mentioned indicators between the two groups were compared, and statistically significant indicators were included in a binary multivariate Logistic regression analysis to explore the independent influencing factors of FI during EN in ICU patients.
RESULTS:
A total of 683 ICU patients were included, with 57.10% (390/683) incidence of FI during EN. The most common FI symptom was diarrhea (41.58%), followed by gastric retention, reflux, abdominal distension, nausea, abdominal pain, vomiting, and aspiration, with blood in stool being the least common (3.37%). Compared to the EN tolerance group, the EN intolerance group had significantly higher proportions of patients aged ≥60 years, undergoing mechanical ventilation, receiving analgesic and sedative medications, having hyperglycemia, using short-peptide EN fluids, receiving continuous EN, and having a feeding rate > 40 mL/h (all P < 0.05). The binary multivariate Logistic regression analysis revealed that age ≥60 years [odds ratio (OR) = 1.738, 95% confidence interval (95%CI) was 1.241-2.436, P = 0.001], continuous EN (OR = 0.534, 95%CI was 0.377-0.756, P < 0.001), use of analgesic medications (OR = 1.701, 95%CI was 1.139-2.539, P = 0.009), hyperglycemic state (OR = 2.794, 95%CI was 1.999-3.907, P < 0.001), and tube feeding rate > 40 mL/h (OR = 1.018, 95%CI was 1.009-1.027, P < 0.001) were independent risk factors for FI during EN in ICU patients.
CONCLUSIONS
The incidence of FI during EN in ICU patients is relatively high and influenced by age, EN methods, analgesic medications, hyperglycemic state, and tube feeding rate. Therefore, healthcare professionals need to accurately identify the risk factors for FI and actively implement effective intervention measures to reduce the incidence of FI and improve patient outcomes.
Humans
;
Retrospective Studies
;
Enteral Nutrition/methods*
;
Intensive Care Units
;
Case-Control Studies
;
Male
;
Female
;
APACHE
;
Logistic Models
;
Diarrhea/epidemiology*
;
Respiration, Artificial/adverse effects*
;
Middle Aged
;
Aged
6.Application of transport ventilator in the inter-hospital transport of critically ill children.
Yuan-Hong YUAN ; Hui ZHANG ; Zheng-Hui XIAO ; Xiu-Lan LU ; Zhi-Yue XU ; Xin-Ping ZHANG ; Xia-Yan KANG ; Xiao-Ping ZHAO ; Li-Fen ZHU
Chinese Journal of Contemporary Pediatrics 2023;25(3):284-288
OBJECTIVES:
To study the application value of transport ventilator in the inter-hospital transport of critically ill children.
METHODS:
The critically ill children in Hunan Children's Hospital who were transported with or without a transport ventilator were included as the observation group (from January 2019 to January 2020; n=122) and the control group (from January 2018 to January 2019; n=120), respectively. The two groups were compared in terms of general data, the changes in heart rate, respiratory rate, and blood oxygen saturation during transport, the incidence rates of adverse events, and outcomes.
RESULTS:
There were no significant differences between the two groups in sex, age, oxygenation index, pediatric critical illness score, course of disease, primary disease, heart rate, respiratory rate, and transcutaneous oxygen saturation before transport (P>0.05). During transport, there were no significant differences between the two groups in the changes in heart rate, respiratory rate, and transcutaneous oxygen saturation (P>0.05). The incidence rates of tracheal catheter detachment, indwelling needle detachment, and sudden cardiac arrest in the observation group were lower than those in the control group during transport, but the difference was not statistically significant (P>0.05). Compared with the control group, the observation group had significantly shorter duration of mechanical ventilation and length of stay in the pediatric intensive care unit and significantly higher transport success rate and cure/improvement rate (P<0.05).
CONCLUSIONS
The application of transport ventilator in the inter-hospital transport can improve the success rate of inter-hospital transport and the prognosis in critically ill children, and therefore, it holds promise for clinical application in the inter-hospital transport of critically ill children.
Child
;
Humans
;
Critical Illness
;
Respiration, Artificial/adverse effects*
;
Intensive Care Units, Pediatric
;
Ventilators, Mechanical
;
Prognosis
7.Effects of Tanreqing Injection on ICU Mortality among ICU Patients Receiving Mechanical Ventilation: Time-Dependent Cox Regression Analysis of A Large Registry.
Wen WANG ; Qiao HE ; Ming-Qi WANG ; Jia-Yue XU ; Peng JI ; Rui ZHANG ; Kang ZOU ; Xin SUN
Chinese journal of integrative medicine 2023;29(9):782-790
OBJECTIVE:
To assess whether the use of Tanreqing (TRQ) Injection could show improvements in time to extubation, intensive care unit (ICU) mortality, ventilator-associated events (VAEs) and infection-related ventilator associated complication (IVAC) among patients receiving mechanical ventilation (MV).
METHODS:
A time-dependent cox-regression analysis was conducted using data from a well-established registry of healthcare-associated infections at ICUs in China. Patients receiving continuous MV for 3 days or more were included. A time-varying exposure definition was used for TRQ Injection, which were recorded on daily basis. The outcomes included time to extubation, ICU mortality, VAEs and IVAC. Time-dependent Cox models were used to compare the clinical outcomes between TRQ Injection and non-use, after controlling for the influence of comorbidities/conditions and other medications with both fixed and time-varying covariates. For the analyses of time to extubation and ICU mortality, Fine-Gray competing risk models were also used to measure competing risks and outcomes of interest.
RESULTS:
Overall, 7,685 patients were included for the analyses of MV duration, and 7,273 patients for the analysis of ICU mortality. Compared to non-use, patients with TRQ Injection had a lower risk of ICU mortality (Hazards ratios (HR) 0.761, 95% CI, 0.581-0.997), and was associated with a higher hazard for time to extubation (HR 1.105, 95% CI, 1.005-1.216), suggesting a beneficial effect on shortened time to extubation. No significant differences were observed between TRQ Injection and non-use regarding VAEs (HR 1.057, 95% CI, 0.912-1.225) and IVAC (HR 1.177, 95% CI, 0.929-1.491). The effect estimates were robust when using alternative statistic models, applying alternative inclusion and exclusion criteria, and handling missing data by alternative approaches.
CONCLUSION
Our findings suggested that the use of TRQ Injection might lower mortality and improve time to extubation among patients receiving MV, even after controlling for the factor that the use of TRQ changed over time.
Humans
;
Respiration, Artificial/adverse effects*
;
Intensive Care Units
;
Proportional Hazards Models
;
Registries
;
Length of Stay
8.A systematic review of the safety and tolerability evaluation of enteral nutrition in a prone position with acute respiratory distress syndrome.
Chinese Critical Care Medicine 2023;35(9):968-974
OBJECTIVE:
To systematically review safety and tolerance of enteral nutrition (EN) in a prone position, as well as the risks of increased gastric residual volume (GRV), vomiting, aspiration, and ventilator-associated pneumonia, and determine the ways to improve EN tolerance in patients with acute respiratory distress syndrome (ARDS).
METHODS:
Databases including PubMed, Embase and Wanfang Medical data of the English and Chinese literatures were retrieved up from January 1979 to January 2022 to collet the randomized controlled trial (RCT), non-RCT, and observational studies, concerning safety and tolerance of EN in a prone position with ARDS. All trials must have a minimum of two patient groups, one of which must be prone to ARDS and receive EN. Data searching extracting and quality evaluation were assessed by two reviewers independently. RevMan 5.4 software was used for analysis.
RESULTS:
A total of 9 studies were included, including 2 RCTs, 2 non-RCTs, 4 prospective observational studies, and 1 retrospective observational study. The starting and increasing rate of EN were typically well tolerated in the prone position compared to the supine position in patients with ARDS, there was no significant increase in GRV (mL: 95 vs. 110), and the incidence of vomiting was not noticeably higher (0%-35% vs. 33%-57%). The incidence of ventilator-associated pneumonia with EN was not significantly higher in the prone position than in the supine position in patients with ARDS (6%-35% vs. 15%-24%). Aspiration occurred at a similar rate in patients in the nasogastric tube and post-pyloric feeding groups with EN in patients with ARDS in the prone position (22% vs. 20%). EN tolerability with nasogastric and nasojejunal tubes was similar in prone positions, with no significant difference in EN intolerance incidences (15% vs. 22%). Head elevation (30 degree angle-45 degree angle) improved EN tolerance in the prone position in patients with ARDS, thereby increasing the early EN dose [odds ratio (OR) = 0.48, 95% confidence interval (95%CI) was 0.22-1.08, P = 0.08]. Additionally, prophylactic application of gastrointestinal motility drugs, such as erythromycin, at the start of EN in a prone position significantly improved patients' EN tolerance (OR = 1.14, 95%CI was 0.63-2.05, P = 0.67).
CONCLUSIONS
The use of gastric tube for EN in prone position and similar feeding speed to the supine position in patients with ARDS is safe and well tolerated. The initiation and dosing of EN should not be delayed in the prone position. EN tolerance may be increased by elevating the head of the bed during enteral feeding in a prone position, and gastrointestinal motility medications should be promptly administered with EN initiation in patients with ARDS.
Humans
;
Pneumonia, Ventilator-Associated/etiology*
;
Enteral Nutrition
;
Prone Position
;
Respiration, Artificial/adverse effects*
;
Respiratory Distress Syndrome/etiology*
;
Randomized Controlled Trials as Topic
;
Observational Studies as Topic
9.A new type of artificial airway sealer used between artificial airway and ventilator pipeline.
Chinese Critical Care Medicine 2023;35(9):991-994
The need for mechanical ventilation due to severe hypoxemia and acute respiratory distress syndrome has increased dramatically in the global pandemic of severe respiratory infectious diseases. In clinical scenarios, it is sometimes necessary to briefly disconnect the ventilator pipeline from the artificial airway. Still, this operation can lead to a sharp drop in airway pressure, which is contrary to the protective lung ventilation strategy and increases the risk of environmental exposure to bioaerosol, posing a serious threat to patients and medical workers. At present, there is yet to be a practical solution. A new artificial airway device was designed by the medical staff from the department of critical care medicine of Beijing Tiantan Hospital, Capital Medical University, based on many years of research experience in respiratory support therapy, and recently obtained the National Utility Model Patent of China (ZL 2019 2 0379605.4). The device comprises two connecting pipes, the sealing device body, and the globe valve represented by the iridescent optical ring. It has a simple structure, convenient operation, and low production cost. The device is installed between the artificial airway and the ventilator pipeline and realizes the instantaneous sealing of the artificial airway by adjusting the shut-off valve. Using this device to treat mechanically ventilated patients can minimize the ventilator-induced lung injury caused by the repeated disconnection of pipelines, avoid iatrogenic transmission of bioaerosols, and realize dual protection for patients and medical workers. It has extensive clinical application prospects and high health and economic value.
Humans
;
Respiration, Artificial/adverse effects*
;
Ventilators, Mechanical/adverse effects*
;
Respiratory Distress Syndrome/therapy*
;
Ventilator-Induced Lung Injury/prevention & control*
;
Hypoxia/complications*
10.Research on the mechanism of mechanical ventilation induced endoplasmic reticulum stress promoting mechanical ventilation-induced pulmonary fibrosis.
Ri TANG ; Jinhua FENG ; Shuya MEI ; Qiaoyi XU ; Yang ZHOU ; Shunpeng XING ; Yuan GAO ; Zhengyu HE ; Zhiyun ZHANG
Chinese Critical Care Medicine 2023;35(11):1171-1176
OBJECTIVE:
To demonstrate the mechanism of mechanical ventilation (MV) induced endoplasmic reticulum stress (ERS) promoting mechanical ventilation-induced pulmonary fibrosis (MVPF), and to clarify the role of angiotensin receptor 1 (AT1R) during the process.
METHODS:
The C57BL/6 mice were randomly divided into four groups: Sham group, MV group, AT1R-shRNA group and MV+AT1R-shRNA group, with 6 mice in each group. The MV group and MV+AT1R-shRNA group mechanically ventilated for 2 hours after endotracheal intubation to establish MVPF animal model (parameter settings: respiratory rate 70 times/minutes, tidal volume 20 mL/kg, inhated oxygen concentration 0.21). The Sham group and AT1R-shRNA group only underwent intubation after anesthesia and maintained spontaneous breathing. AT1R-shRNA group and MV+AT1R-shRNA group were airway injected with the adeno-associated virus one month before modeling to inhibit AT1R gene expression in lung tissue. The expressions of AT1R, ERS signature proteins [immunoglobulin heavy chain-binding protein (BIP), protein disulfide isomerase (PDI)], fibrosis signature proteins [collagen I (COL1A1), α-smooth muscle actin (α-SMA)] in lung tissues were detected by immunofluorescence and Western blotting. Hematoxylin-eosin (HE) staining was used to evaluate lung injury and Masson staining was used to evaluate pulmonary fibrosis.
RESULTS:
Compared with the Sham group, the degree of pulmonary fibrosis and lung injury were more significant in the MV group. In the MV group, the protein expressions of AT1R, BIP, PDI, COL1A1 and α-SMA were increased (AT1R/β-actin: 1.40±0.02 vs. 1, BIP/β-actin: 2.79±0.07 vs. 1, PDI/β-actin: 2.07±0.02 vs. 1, COL1A1/α-Tubulin: 2.60±0.15 vs. 1, α-SMA/α-Tubulin: 2.80±0.25 vs. 1, all P < 0.01). The number of E-cad+/AT1R+ and E-cad+/BIP+ cells in lung tissue increased, and the fluorescence intensity of COL1A1 and α-SMA increased. Compared with the MV group, the degree of pulmonary fibrosis and lung injury were significantly relieved in the MV+AT1R-shRNA group. In the MV+AT1R-shRNA group, the protein expressions of AT1R, BIP, PDI, COL1A1 and α-SMA were decreased (AT1R/β-actin: 0.53±0.03 vs. 1.40±0.02, BIP/β-actin: 1.73±0.15 vs. 2.79±0.07, PDI/β-actin: 1.04±0.07 vs. 2.07±0.02, COL1A1/α-Tubulin: 1.29±0.11 vs. 2.60±0.15, α-SMA/α-Tubulin: 1.27±0.10 vs. 2.80±0.25, all P < 0.01). The number of E-cad+/AT1R+ and E-cad+/BIP+ cells in lung tissue decreased, and the fluorescence intensity of COL1A1 and α-SMA decreased. There was no statistically significant difference in the indicators between AT1R-shRNA group and Sham group.
CONCLUSIONS
MV up-regulate the expression of AT1R in alveolar epithelial cells, activate the AT1R pathway, induce ERS and promote the progression of MVPF.
Mice
;
Animals
;
Pulmonary Fibrosis/chemically induced*
;
Lung Injury
;
Respiration, Artificial/adverse effects*
;
Actins/metabolism*
;
Tubulin
;
Mice, Inbred C57BL
;
Endoplasmic Reticulum Stress
;
RNA, Small Interfering

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