A novel tetratricopeptide-repeat protein, TTP1, forms complexes with glutamyl-tRNA reductase and protochlorophyllide oxidoreductase during tetrapyrrole biosynthesis.

The biosynthesis of the tetrapyrrole end-products chlorophyll and heme depends on a multifaceted control mechanism that acts primarily at the post-translational level upon the rate-limiting step of 5-aminolevulinic acid synthesis and upon light-dependent protochlorophyllide oxidoreductase (POR). These regulatory processes require auxiliary factors that modulate the activity, stability, complex formation, and subplastidal localization of the relevant proteins. Together, they ensure optimal metabolic flow during the day and at night. As an Arabidopsis homolog of the POR-interacting tetratricopeptide-repeat protein (Pitt) first reported in Synechocystis, we characterize tetrapyrrole biosynthesis-regulating tetratricopeptide-repeat protein1 (TTP1). TTP1 is a plastid-localized, membrane-bound factor that interacts with POR, the Mg protoporphyrin monomethylester cyclase CHL27, glutamyl-tRNA reductase (GluTR), GluTR-binding protein, and FLUORESCENCE IN BLUE LIGHT. Lack of TTP1 leads to accumulation of GluTR, enhanced 5-aminolevulinic acid synthesis and lower levels of POR. Knockout mutants show enhanced sensitivity to reactive oxygen species and a slower greening of etiolated seedlings. Based on our studies, the interaction of TTP1 with GluTR and POR does not directly inhibit their enzymatic activity and contribute to the control of 5-aminolevulinic acid synthesis. Instead, we propose that TTP1 sequesters a fraction of these proteins on the thylakoid membrane, and contributes to their stability.

PROGRAMMED CELL DEATH8 interacts with tetrapyrrole biosynthesis enzymes and ClpC1 to maintain homeostasis of tetrapyrrole metabolites in Arabidopsis.

Tetrapyrrole biosynthesis (TBS) is a dynamically and strictly regulated process. Disruptions in tetrapyrrole metabolism influence many aspects of plant physiology, including photosynthesis, programmed cell death (PCD), and retrograde signaling, thus affecting plant growth and development at multiple levels. However, the genetic and molecular basis of TBS is not fully understood. We report here PCD8, a newly identified thylakoid-localized protein encoded by an essential gene in Arabidopsis. PCD8 knockdown causes a necrotic phenotype due to excessive chloroplast damage. A burst of singlet oxygen that results from overaccumulated tetrapyrrole intermediates upon illumination is suggested to be responsible for cell death in the knockdown mutants. Genetic and biochemical analyses revealed that PCD8 interacts with ClpC1 and a number of TBS enzymes, such as HEMC, CHLD, and PORC of TBS. Taken together, our findings uncover the function of chloroplast-localized PCD8 and provide a new perspective to elucidate molecular mechanism of how TBS is finely regulated in plants.

In vivo functional analysis of the structural domains of FLUORESCENT (FLU).

The control of chlorophyll (Chl) synthesis in angiosperms depends on the light-operating enzyme protochlorophyllide oxidoreductase (POR). The interruption of Chl synthesis during darkness requires suppression of the synthesis of 5-aminolevulinic acid (ALA), the first precursor molecule specific for Chl synthesis. The inactivation of glutamyl-tRNA reductase (GluTR), the first enzyme in tetrapyrrole biosynthesis, accomplished the decreased ALA synthesis by the membrane-bound protein FLUORESCENT (FLU) and prevents overaccumulation of protochlorophyllide (Pchlide) in the dark. We set out to elucidate the molecular mechanism of FLU-mediated inhibition of ALA synthesis, and explored the role of each of the three structural domains of mature FLU, the transmembrane, coiled-coil and tetratricopeptide repeat (TPR) domains, in this process. Efforts to rescue the FLU knock-out mutant with truncated FLU peptides revealed that, on its own, the TPR domain is insufficient to inactivate GluTR, although tight binding of the TPR domain to GluTR was detected. A truncated FLU peptide consisting of transmembrane and TPR domains also failed to inactivate GluTR in the dark. Similarly, suppression of ALA synthesis could not be achieved by combining the coiled-coil and TPR domains. Interaction studies revealed that binding of GluTR and POR to FLU is essential for inhibiting ALA synthesis. These results imply that all three FLU domains are required for the repression of ALA synthesis, in order to avoid the overaccumulation of Pchlide in the dark. Only complete FLU ensures the formation of a membrane-bound ternary complex consisting at least of FLU, GluTR and POR to repress ALA synthesis.

Health-related quality of life and associated factors in Chinese menstrual migraine patients: a cross-sectional study.

BACKGROUND: Menstrual migraine is a particular form of migraine with a significant impact on the quality of life for women afflicted. Presently, no study has reported the quality of life in menstrual migraine patients. This work aims to assess the health-related quality of life and identify its associated factors among Chinese menstrual migraine patients. METHODS: The cross-sectional study group consisted of 109 patients with menstrual migraine, and the control group consisted of 397 female patients with non-menstrual migraine. In total, 506 patients completed questionnaires for demographic and clinical information, the Self-rating Idea of Suicide Scale, the Hamilton Depression Scale, the Hamilton Anxiety Scale, the Headache Impact Test-6, the Perceived Social Support Scale, the Pittsburgh Sleep Quality Index. Health-related quality of life was measured using the 36-Item Short Form Survey. RESULTS: Compared with non-menstrual migraine patients, five dimensions of health-related quality of life were all found to be significantly impaired in menstrual migraine patients. Headache frequency (ß = - 0.218, P = 0.014), the impact of headache on daily life (ß = - 0.270, P = 0.002), depression symptoms (ß = - 0.345, P < 0.001) were significantly associated with physical component summary, depression symptoms (ß = - 0.379, P < 0.001), social support (ß = 0.270, P < 0.001), suicidal ideation (ß = - 0.344, P < 0.001) were closely related to mental component summary. CONCLUSION: Menstrual migraine patients had a significantly poorer health-related quality of life in many domains than non-menstrual migraine patients. Headache frequency, the impact of headache on daily life, depression symptoms, social support, and suicidal ideation were significantly associated with health-related quality of life in menstrual migraine patients. TRIAL REGISTRATION: ChiCTR1800014343. This study was registered prospectively on 7 January 2018 at Chinese Clinical Trial registry. http://www.chictr.org.cn/showproj.aspx?proj=24526.

MicroRNA-19b Mediates Lung Epithelial-Mesenchymal Transition via Phosphatidylinositol-3,4,5-Trisphosphate 3-Phosphatase in Response to Mechanical Stretch.

Lung epithelial-mesenchymal transition (EMT) plays an important role in ventilation-associated lung fibrosis, which may contribute to the poor outcome of patients with acute respiratory distress syndrome. Because microRNAs control and modulate normal physiological and pathophysiological processes, we investigated the role of microRNAs in the development of acute respiratory distress syndrome-associated EMT in response to mechanical stress. In the current study, primary human alveolar epithelial type II (AEII) cells were subjected to cyclic stretch that resulted in EMT profiles with decreased gene expression of cytokeratin-8, E-cadherin, and surfactant protein B, and increased expression of vimentin, α-smooth muscle actin, and N-cadherin. Microarray analysis revealed that the expression of microRNA-19b (miR-19b) was up-regulated in the AEII cells, and real-time polymerase chain reaction showed that the expression of miR-19b increased in both the AEII cells and the primary human small-airway epithelial cells. Overexpression of miR-19b in small-airway epithelial cells promoted the mechanical stretch-induced EMT phenotypes, whereas inhibition of miR-19b attenuated it. The inhibitory effect of miR-19b was attributed to enhanced signaling of phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase (PTEN), leading to inactivation of the AKT pathway. Restoration of PTEN expression or inhibition of AKT phosphorylation suppressed the mechanical stretch-induced EMT phenotypes. We further demonstrated that the mechanical stretch-induced miR19 expression was regulated by the focal adhesion kinase-Rho pathway. In conclusion, we found that miR-19b plays a key role in the development of the EMT phenotype through down-regulation of PTEN in human lung epithelial cells in response to mechanical stretch. The miR-19b-PTEN signaling pathway may serve as a novel therapeutic target in the context of ventilator-associated lung fibrosis.

[Study on the Fingerprint of Kingkong Zedoary Turmeric Oil].

OBJECTIVE: To study the fingerprint of Zedoary Turmeric Oil (ZTO) as the bulk drug of Kingkong Elemene for making it safe, effective, stable, and controllable. METHODS: Fingerprints were detected by gas chromatography. ß-elemene peak was regarded as reference peak (S). The relative peak area of each common peak and the relative retention time were calculated. With a total of modes for reference, the fingerprints of 10 batches of Kingkong ZTO were detected, and their similarity was calculated by traditional Chinese medicine (TCM) fingerprint similarity calculation software. RESULTS: The determination method was stable and reliable. Totally 19 common characteristic peaks of Kingkong ZTO was found. The fingerprint similarity of these batches of Kingkong ZTO were not lower than 0.96. CONCLUSIONS: Gas chromatography for detecting the fingerprint of Kingkong ZTO was reliable and repeatable. The established fingerprint of Kingkong ZTO could guarantee the quality stability and safety of different product batches.

Effervescent-salt-assisted dispersive micro-solid-phase extraction using mesoporous hybrid materials coupled with ultra-performance liquid chromatography for the determination of trace-level compounds in complicated plant preparations.

A novel effervescent-salt-assisted dispersive micro-solid-phase extraction using mesoporous hybrid materials was developed for the extraction of minute traces of constituents in complicated plant preparations. In this study, a special tablet containing carbon dioxide sources (sodium dihydrogenphosphate and sodium carbonate) and the sorbent (mesoporous hybrid materials) was prepared. The effects of different parameters influencing the extraction efficiency such as the concentration of salts, the type and concentration of mesoporous material, pH of diluent, and desorption solvents were investigated and optimized. Results show that the proposed method using green solvents (water) as extraction solutions required low consumption of sample amount and obtained high enrichment efficiency. Moreover, under optimized conditions, the tested tanshinones exhibited good linearity (r(2) > 0.994) in the concentration range of 0.5 to 80 ng mL(-1). The limits of detection values were lower than 0.0803 pg using UV-visible detection. The developed method was successfully applied for the analysis of trace tanshinones in compound Danshen dripping pill and Danqi tablet samples.

Proteomic analysis of lung tissue in a rat acute lung injury model: identification of PRDX1 as a promoter of inflammation.

Acute respiratory distress syndrome (ARDS) remains a high morbidity and mortality disease entity in critically ill patients, despite decades of numerous investigations into its pathogenesis. To obtain global protein expression changes in acute lung injury (ALI) lung tissues, we employed a high-throughput proteomics method to identify key components which may be involved in the pathogenesis of ALI. In the present study, we analyzed lung tissue proteomes of Pseudomonas aeruginosa-induced ALI rats and identified eighteen proteins whose expression levels changed more than twofold as compared to normal controls. In particular, we found that PRDX1 expression in culture medium was elevated by a lipopolysaccharide (LPS) challenge in airway epithelial cells in vitro. Furthermore, overexpression of PRDX1 increased the expression of proinflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α), whereas knockdown of PRDX1 led to downregulated expression of cytokines induced by LPS. In conclusion, our findings provide a global alteration in the proteome of lung tissues in the ALI rat model and indicate that PRDX1 may play a critical role in the pathogenesis of ARDS by promoting inflammation and represent a novel strategy for the development of new therapies against ALI.

Role of phosphoglucomutase in regulating trehalose metabolism in Nilaparvata lugens.

Phosphoglucomutase (PGM) is a key enzyme in glycolysis and gluconeogenesis, regulating both glycogen and trehalose metabolism in insects. In this study, we explored the potential function of phosphoglucomutase (PGM) using RNA interference technology in Nilaparvata lugens, the brown planthopper. PGM1 and PGM2 were found highly expressed in the midgut of brown planthoppers, with different expression levels in different instar nymphs. The glycogen, glucose, and trehalose levels were also significantly increased after brown planthoppers were injected with dsRNA targeting PGM1 (dsPGM1) or PGM2 (dsPGM2). In addition, injection of dsPGM1 or dsPGM2 resulted in increased membrane-bound trehalase activity but not soluble trehalase activity. Furthermore, the expression of genes related to trehalose and glycogen metabolism decreased significantly after injection with dsPGM1 and dsPGM2. The expression levels of genes involved in chitin metabolism in the brown planthopper were also significantly decreased and the insects showed wing deformities and difficulty molting following RNAi. We suggest that silencing of PGM1 and PGM2 expression directly inhibits trehalose metabolism, leading to impaired chitin synthesis.

Review of Anemone raddeana Rhizome and its pharmacological effects.

The chemical compositions of Anemone raddeana Rhizome, a kind of traditional Chinese medicine, were reviewed, along with its bioactivity and pharmacological properties and method improvements of extracting and detecting triterpenoid saponins. A. raddeana Rhizome is used to treat neuralgia and rheumatism, and is rich in triterpenoid saponins, most of which are pentacyclic, with oleanane as the nucleus. So far, 37 triterpenoid saponins have been determined from the herb. Its reported bioactivity and pharmacological properties have been described as anticancerous, antimicrobial, anti-inflammatory, analgesic, antipyretic, anticonvulsive, antihistaminic, and sedative. It has also been used for the induction of the humoral immune response and treatment of liver fibrosis in chronic hepatitis. However, the herb also has hemolytic effects and can be toxic, which limits its clinical application. Further studies are needed on the pharmaceutical functions, mechanisms, and immunological responses to contribute to the herb's clinical applications.

Interleukin-10/lymphocyte ratio predicts mortality in severe septic patients.

BACKGROUND: Immunosuppression is common even in the early stage of severe sepsis. Interleukin-10 (IL-10) secretion and lymphocyte exhaustion are the main features of sepsis-induced immunosuppression. However, the relationship between IL-10 and the lymphocyte is still unclear. We investigated if IL-10/lymphocyte ratio (IL10LCR) were associated with mortality in severe septic patients. METHODS: Adult patients with severe sepsis admitted to ICU of the First Affiliated Hospital of Guangzhou Medical University were identified from October 2012 to August 2013. Within 24 hours of ICU admission, peripheral whole blood was collected for the measurement of IL-10 using commercial multiplex bead-based assay kits and determination of lymphocyte count from laboratory data. The primary outcome was 28-day mortality. RESULTS: A total of 63 severe sepsis patients were identified. There were 20 (32%) patients died within 28 days. IL10LCR in non-survival patients was significantly higher than survival patients (median (IQR) 36.78 (12.34-79.63) ng/ml2 versus 11.01(5.41-27.50) ng/ml2, P = 0.002). Correlation analysis showed that IL10LCR was significantly correlated with APACHE II score (Spearman's rho = 0.424, P<0.001). The receiver operating characteristic (ROC) curves showed the area under the curve was 0.749 for IL10LCR level to predict 28-day mortality with sensitivity and specificity at 70.0% and 74.4%, respectively. At an optimal cutoff of 23.39ng/ml2, Kaplan-Meier curve showed survival in patients with IL10LCR level above 23.39ng/ml2 was significantly lower than in patients with IL10LCR level less than 23.39ng/ml2 (P = 0.001 by log-rank test). CONCLUSION: IL10LCR level is significantly associated with the severity and outcome of severe septic patients. It may serve as a biomarker for sepsis-induced immunosuppression.

Trace matrix solid phase dispersion using a molecular sieve as the sorbent for the determination of flavonoids in fruit peels by ultra-performance liquid chromatography.

A simple, rapid, and highly selective trace matrix solid phase dispersion (MSPD) technique, coupled with ultra-performance liquid chromatography-ultraviolet detection, was proposed for extracting flavonoids from orange fruit peel matrices. Molecular sieve SBA-15 was applied for the first time as a solid support in trace MSPD. Parameters, such as the type of dispersant, mass ratio of the sample to the dispersant, grinding time, and elution pH, were optimized in detail. The optimal extraction conditions involved dispersing a powdered fruit peel sample (25 mg) into 25mg of SBA-15 and then eluting the target analytes with 500 µL of methanol. A satisfactory linearity (r(2) > 0.9990) was obtained, and the calculated limits of detection reached 0.02-0.03 µg/mL for the compounds. The results showed that the method developed was successfully applied to determine the content of flavonoids in complex fruit peel matrices.

Trace-chitosan-wrapped multi-walled carbon nanotubes as a new sorbent in dispersive micro solid-phase extraction to determine phenolic compounds.

This report describes the use of trace-chitosan-wrapped multi-walled carbon nanotubes (CS-MWCNTs) as a sorbent material in dispersive micro solid-phase extraction (DMSPE), which was combined with ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry to analyze phenolic compounds in chrysanthemum tea and a chrysanthemum beverage. In this study, for the first time, CS-MWCNTs were used as a sorbent for this microextraction mode. Moreover, the proposed method exhibits the advantages of simplicity, rapidity, small sample amount and ease of operation. Furthermore, all of the important parameters that affect the extraction efficiency, such as the sorbent, pH, extraction time and type of elution solvent, were investigated and optimized in the DMSPE. Under the optimized extraction condition, the limit of detection, which was calculated based on a signal-to-noise ratio of 3, was 0.22-16.19ngmL(-1). Satisfactory recovery values of 89-106% were obtained for the tested samples. The results show that the developed method was successfully applied to determine the content of chlorogenic acid and flavonoids in complex chrysanthemum samples.

Effervescence and graphitized multi-walled carbon nanotubes assisted microextraction for natural antioxidants by ultra high performance liquid chromatography with electrochemical detection and quadrupole time-of-flight tandem mass spectrometry.

In this article, effervescence and graphitized multi-walled carbon nanotubes assisted microextraction was first developed for the extraction of antioxidants in hawthorn samples. The use of an effervescent tablet composed of sodium dihydrogen phosphate, sodium carbonate and micro-scale carboxyl graphitized multi-walled carbon nanotubes (extraction sorbent) was the core of the method. In this study, ultra high performance liquid chromatography coupled with electrochemical detection and quadrupole time-of-flight tandem mass spectrometry was performed for qualitative and quantitative analyses of target analytes in hawthorn foodstuffs. Several experimental factors, such as amount of effervescent salts, the sorbent, elution time and elution solvent, were systematically assessed. Under the optimized conditions, a good linearity with R values better than 0.9980 was obtained. The detection limits estimated at a signal-to-noise ratio of 3:1 were ranging from 0.01 to 0.18ng/mL. These results suggested that the proposed method could be an alternative and promising sample preparation tool in future food analysis.

Construction and management of ARDS/sepsis registry with REDCap.

OBJECTIVE: The study aimed to construct and manage an acute respiratory distress syndrome (ARDS)/sepsis registry that can be used for data warehousing and clinical research. METHODS: The workflow methodology and software solution of research electronic data capture (REDCap) was used to construct the ARDS/sepsis registry. Clinical data from ARDS and sepsis patients registered to the intensive care unit (ICU) of our hospital formed the registry. These data were converted to the electronic case report form (eCRF) format used in REDCap by trained medical staff. Data validation, quality control, and database management were conducted to ensure data integrity. RESULTS: The clinical data of 67 patients registered to the ICU between June 2013 and December 2013 were analyzed. Of the 67 patients, 45 (67.2%) were classified as sepsis, 14 (20.9%) as ARDS, and eight (11.9%) as sepsis-associated ARDS. The patients' information, comprising demographic characteristics, medical history, clinical interventions, daily assessment, clinical outcome, and follow-up data, was properly managed and safely stored in the ARDS/sepsis registry. Data efficiency was guaranteed by performing data collection and data entry twice weekly and every two weeks, respectively. CONCLUSIONS: The ARDS/sepsis database that we constructed and manage with REDCap in the ICU can provide a solid foundation for translational research on the clinical data of interest, and a model for development of other medical registries in the future.

Highly sensitive analysis of flavonoids by zwitterionic microemulsion electrokinetic chromatography coupled with light-emitting diode-induced fluorescence detection.

A rapid zwitterionic microemulsion electrokinetic chromatography (ZI-MEEKC) approach coupled with light-emitting-diode-induced fluorescence (LED-IF, 480nm) detection was proposed for the analysis of flavonoids. In the optimization process, we systematically investigated the separation conditions, including the surfactants, cosurfactants, pH, buffers and fluorescence parameters. It was found that the baseline separation of the seven flavonoids was obtained in less than 5min with a running buffer consisting of 92.9% (v/v) 5mM sodium borate, 0.6% (w/v) ZI surfactant, 0.5% (w/v) ethyl acetate and 6.0% (w/v) 1-butanol. High sensitivity was obtained by the application of LED-IF detection. The limits of detection for seven flavonoids were in the range of 3.30×10(-8) to 2.15×10(-6)molL(-1) without derivatization. Ultimately, the detection method was successfully applied to the analysis of flavonoids in hawthorn plant and food products with satisfactory results.

[Effects of cyclic stretch on the induction of the transdifferentiation in human lung epithelial cells].

OBJECTIVE: To investigate the effect of mechanical stretch induced epithelial-mesenchymal transition in human lung epithelial cells BEAS-2B in vitro. METHODS: The human lung epithelial cells BEAS-2B were subjected to cyclic stretch by the FX-5000T system at 0.33 Hz of 10% or 20% elongation for 24, 48 and 72 hours respectively. The morphologic changes were observed by microscopy. The mRNA and protein expressions of E-cadherin, Cytokeratin-8 (CK-8), α-smooth muscle actin (α-SMA) and Vimentin were evaluated by immunofluorescence before and after mechanical stretch and fluorescent quantitation reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: (1) When stretch by 20% elongation for 48 hours, the morphological changes in BEAS-2B cells from cobblestone-like structure to elongated shape and obviously when stretch for up to 72 hours, while 10% elongation showed no significant morphological changes comparing to control. (2) Decreasing E-cadherin and CK-8 protein expression was associated with increased immunostaining for α-SMA protein at 72 hours after 20% mechanical stretch. (3) Expression of E-cadherin mRNA was decreased to 0.388±0.056 and 0.247±0.064 after 20% mechanical stretch for 48 hours and 72 hours compared with control without stretch (set 1, both P<0.05), expression of CK-8 mRNA was decreased to 0.436±0.060 at 72 hours after 20% mechanical stretch (P<0.01), α-SMA mRNA was increased to 1.437±0.267 (48 hours) and 1.261±0.247 (72 hours) after 20% mechanical stretch (both P<0.05), and Vimentin mRNA was increased to 1.679±0.172 (48 hours) after 20% mechanical stretch (P<0.05). Expression of E-cadherin mRNA was decreased to 0.387±0.081 at 72 hours after 10% mechanical stretch (P<0.05), Vimentin mRNA was increased to 1.688±0.179 at 48 hours after 10% mechanical stretch while other markers showed no significant changes comparing with control. CONCLUSIONS: Excessive mechanical stretch could induce epithelial-mesenchymal transition in lung epithelial cells BEAS-2B in vitro.

[Effects of cyclic stretch on expression of cytokines and intercellular adhesion molecule-1 in human pulmonary artery endothelial cell].

OBJECTIVE: To observe the effects of cyclic stretch on expression of cytokines and adhesion molecules in human pulmonary artery endothelial cells (HPAECs), herein to provide a theoretical basis to ventilator-induced lung injury (VILI). METHODS: HPAECs were subjected to cyclic stretch by the Flexcell FX-5000T system at 0.5 Hz of 10% or 20% elongation for 3, 6, 12, 24 hours respectively. The mRNA and protein expression of interleukin (IL-6, IL-8), monocyte chemotactic protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) was determined by fluorescent quantitation reverse transcription-polymerase chain reaction (qRT-PCR), enzyme linked immunosorbent assay (ELISA) or Western blotting. RESULTS: Increasing the stretch force, the mRNA and protein expression of IL-8, MCP-1, ICAM-1 were up regulated with increasing stretch time. Compared with the control (set 1), after 20% cyclic stretch for 24 hours, IL-8 mRNA expression was up regulated to 1.58±0.10, MCP-1 mRNA expression was up regulated to 2.85±0.52, and ICAM-1 mRNA expression was up regulated to 1.90±0.14 (all P<0.05). Compared with control group, after 20% cyclic stretch for 24 hours, the protein expression of IL-8 and MCP-1 in HPAEC was significantly increased (IL-8: 3401.08±439.60 ng/L vs. 1422.60±66.98 ng/L, MCP-1: 1117.64±237.54 ng/L vs. 307.88±80.84 ng/L, both P<0.05), ICAM-1 protein expression was up regulated to 2.15±0.40 (P<0.05), while the expression of IL-6 mRNA and protein had no statistic difference compared with control group. CONCLUSIONS: Cyclic stretch enhanced the expression of IL-8, MCP-1 and ICAM-1 in an intensity-dependent fashion, so it may be involved in the pathogenesis of lung injury induced by mechanical ventilation.