Assessment of the cancer risk factors of solitary pulmonary nodules.

There are no large samples or exact prediction models for assessing the cancer risk factors of solitary pulmonary nodules (SPNs) in the Chinese population. We retrospectively analyzed the clinical and imaging data of patients with SPNs who underwent computer tomography guided needle biopsy in our hospital from Jan 1st of 2011 to March 30th of 2016. These patients were divided into a development data set and a validation data set. These groups included 1078 and 344 patients, respectively. A prediction model was developed from the development data set and was validated with the validation data set using logistic regression. The predictors of cancer in our model included female gender, age, pack-years of smoking, a previous history of malignancy, nodule size, lobulated and spiculated edges, lobulation alone and spiculation alone. The Area Under the Curves, sensitivity and specificity of our model in the development and validation data sets were significantly higher than those of the Mayo model and VA model (p < 0.001). We established the largest sampling risk prediction model of SPNs in a Chinese cohort. This model is particularly applicable to SPNs > 8 mm in size. SPNs in female patients, as well as SPNs featuring a combination of lobulated and spiculated edges or lobulated edges alone, should be evaluated carefully due to the probability that they are malignant.

Prevention and management of lung cancer in China.

Lung cancer is the leading cause of cancer-related death worldwide. In China, the incidence of lung cancer has grown rapidly, resulting in a large social and economic burden. Several researchers have devoted their studies to lung cancer and have demonstrated that there are many risk factors for lung cancer in China, including tobacco use, environmental pollution, food, genetics, and chronic obstructive pulmonary disease. However, the lung cancer incidence is still growing rapidly in China, and there is an even higher incidence among the younger generation. One explanation may be the triple-neglect situation, in which medical policies that neglect prevention, diagnosis, and supportive care have increased patients' mortality and reduced their quality of life. Therefore, it is necessary to enhance the efficiency of prevention and early diagnosis not only by focusing more attention on treatment but also by drawing more attention to supportive care for patients with lung cancer.

Chinese consensus on early diagnosis of primary lung cancer (2014 version).

The incidence and mortality of lung cancer in China have rapidly increased. Lung cancer is the leading cause of cancer death in China, possibly because of the inadequate early diagnosis of lung cancer. Reaching a consensus on early diagnostic strategies for lung cancer in China is an unmet needed. Recently, much progress has been made in lung cancer diagnosis, such as screening in high-risk populations, the application of novel imaging technologies, and the use of minimally invasive techniques for diagnosis. However, systemic reviews of disease history, risk assessment, and patients' willingness to undergo invasive diagnostic procedures also need to be considered. A diagnostic strategy for lung cancer should be proposed and developed by a multidisciplinary group. A comprehensive evaluation of patient factors and clinical findings should be completed before treatment.

Role of Angptl4 in vascular permeability and inflammation.

BACKGROUND: Angptl4 is a secreted protein involved in the regulation of vascular permeability, angiogenesis, and inflammatory responses in different kinds of tissues. Increases of vascular permeability and abnormality changes in angiogenesis contribute to the pathogenesis of tumor metastasis, ischemic-reperfusion injury. Inflammatory response associated with Angptl4 also leads to minimal change glomerulonephritis, wound healing. However, the role of Angptl4 in vascular permeability, angiogenesis, and inflammation is controversy. Hence, an underlying mechanism of Angptl4 in different kind of tissues needs to be further clarified. METHODS: Keywords such as angptl4, vascular permeability, angiogenesis, inflammation, and endothelial cells were used in search tool of PUBMED, and then the literatures associated with Angptl4 were founded and read. RESULTS: Data have established Angptl4 as the key modulator of both vascular permeability and angiogenesis; furthermore, it may also be related to the progression of metastatic tumors, cardiovascular events, and inflammatory diseases. This view focuses on the recent advances in our understanding of the role of Angptl4 in vascular permeability, angiogenesis, inflammatory signaling and the link between Angptl4 and multiple diseases such as cancer, cardiovascular diseases, diabetic retinopathy, and kidney diseases. CONCLUSIONS: Taken together, Angptl4 modulates vascular permeability, angiogenesis, inflammatory signaling, and associated diseases. The use of Angptl4-modulating agents such as certain drugs, food constituents (such as fatty acids), nuclear factor (such as PPARα), and bacteria may treat associated diseases such as tumor metastasis, ischemic-reperfusion injury, inflammation, and chronic low-grade inflammation. However, the diverse physiological functions of Angptl4 in different tissues can lead to potentially deleterious side effects when used as a therapeutic target. In this regard, a better understanding of the underlying mechanisms for Angptl4 in different tissues is necessary.

Factors associated with the need of biventricular mechanical circulatory support in children with advanced heart failure.

OBJECTIVES: Postimplantation right ventricular dysfunction is associated with increased morbidity and mortality in ventricular assist device (VAD) recipients. This study aimed to determine the preoperative risk factors for severe right heart failure needing biventricular mechanical circulatory support in children with end-stage heart failure. METHODS: We reviewed data from 84 children supported with long-term VADs at the German Heart Institute Berlin between January 1999 and October 2010. Right ventricular assist device (RVAD) support was needed for 24 (29%) patients, and the other 60 (71%) were implanted with left ventricular assist devices (LVADs). RESULTS: The median age at implantation was 7 years (12 days-18 years), and the median support time was 41 days (1-432 days). Of the 84 patients, the overall survival to transplantation or recovery of ventricular function was 69%. Compared with children implanted with LVAD, patients receiving biventricular support had significantly higher postoperative mortality (P = 0.04). The multivariate logistic regression indicated that decreased milrinone use was the only preoperative factor independently associated with increased requirement for biventricular support (odds ratio: 0.1, 95% confidence interval: 0.04-0.64, P = 0.01). Children treated with milrinone preoperatively showed improved survival after implantation (P = 0.04). CONCLUSIONS: Paediatric patients needing biventricular support had significantly higher postoperative mortality. Preoperative milrinone use might decrease the risk of severe right ventricular failure requiring additional RVAD insertion and improve postimplantation survival in children with advanced heart failure.

[The negative enrichment by immunomagnetic beads for tumor cells from malignant pleural effusions].

OBJECTIVE: To establish a method (negative enrichment by immunomagnetic beads) for detection of tumor cells in pleural effusions and to evaluate the sensitivity and specificity of the method for clinical application. METHODS: Five, 10, 20, 50 and 100 A549 (lung adenocarcinoma) cells were labeled with DAPI and added into 20 ml pleural effusions [containing (1 - 10)×10(6)cells] from heart failure patients, followed by immunomagnetic negative enrichment method. Recovered cancer cells were enumerated using a fluorescent microscope. Tumor cells were enriched from pleural effusion samples by means of density gradient centrifugation and negative enrichment by immunomagnetic beads method, followed by identification with cytology analysis (Wright's Giemsa's staining), immunofluorescence staining (IF) and fluorescence in situ hybridization (FISH) using centromere DNA probes of chromosome 7 and 8. Cytology, IF and FISH evaluations were performed in 53 pleural effusion samples, including 36 cases of malignant disease (25 male and 11 female patients aging 40 to 78 years, mean age (63 ± 9) and 17 cases of benign disease (8 male and 9 female patients aging 25 to 81 years, mean age (53 ± 18). RESULTS: After DAPI staining and mixing with pleural effusions from heart failure patients, the cell recovery rates of A549 cells evaluated under fluorescence microscope were 75%, 78%, 82%, 85%, 88%, and the average recovery rate was 81.6%. Using negative enrichment method and density gradient centrifugation combined with cytology analysis, the positive rates of tumor cells in 36 malignant pleural effusion samples were 81% (29/36) and 61% (22/36), respectively (χ(2) = 4.00, P = 0.039). Using negative enrichment method combined with IF, the positive rate of CK18(+), DAPI(+), CD(45)(-) cells was 100%. Moreover, using negative enrichment method combined with FISH analysis, the positive rate of tumor cells was 86% (31/36), much higher than that using density gradient centrifugation combined with cytology analysis (χ(2) = 5.818, P = 0.012). In 17 cases of benign pleural effusions, using negative enrichment method combined with IF, the positive rate was 100%. But other methods didn't find cancer cells from benign pleural effusions. CONCLUSIONS: It was applicable to enrich tumor cells from pleural effusions using negative enrichment method by immunomagnetic beads. This method combined with cytology analysis or FISH significantly enhanced the sensitivity and specificity of tumor cell detection in pleural effusions. But it was difficult to distinguish cancer cells from mesothelial cells using immunofluorescence staining with CK18, DAPI and CD(45) label. More specific markers were needed to recognize tumor cells from pleural effusions.

Pretreatment with anti-flagellin serum delays acute lung injury in rats with sepsis.

OBJECTIVE: This study examined the reduction of sepsis-induced ALI by inhibition of flagellin-stimulated TLR5 signaling. METHODS: Rats were randomly divided into three groups: one group served as the sham-operated group (control group), and the other two groups received the induction of sepsis (sepsis and treatment groups). The treatment group was injected with anti-flagellin serum before induction of sepsis. At 2, 4, 6, 12, 24, and 48 h following induction of sepsis (six time-point subgroups, n = 10 per subgroup), arterial PaO(2), wet/dry (W/D) lung weight ratios, levels of serum and BALF flagellin and TNF-α, pulmonary pathological alterations, and TLR5 mRNA expression in the lungs were examined. RESULTS: Compared to sham-operated rats, septic rats had: increased levels of serum and BALF flagellin at 6, 12, 24, and 48 h; reduced arterial PaO(2); elevated W/D lung weight ratio; increased serum and BALF TNF-α levels; and up-regulated TLR5 mRNA expression at 12, 24, and 48 h (P < 0.01). Pretreatment with anti-flagellin serum, however, significantly inhibited sepsis-associated declines in arterial PaO(2), increased W/D lung weight ratios, elevated serum and BALF TNF-α levels, and up-regulated TLR5 mRNA expression at 24 and 48 h (P < 0.01). CONCLUSION: Neutralizing the actions of circulating flagellin with anti-flagellin serum delayed the development of ALI in rats with sepsis.

Over-expression of PKGIα inhibits hypoxia-induced proliferation, Akt activation, and phenotype modulation of human PASMCs: the role of phenotype modulation of PASMCs in pulmonary vascular remodeling.

The proliferation of pulmonary artery smooth muscle cells (PASMCs) plays a role in pulmonary vascular remodeling (PVR). Recently, it was shown that vascular smooth muscular cell phenotype modulation is important for their proliferation in other diseases. However, little is known about the role of human PASMC phenotype modulation in the proliferation induced by hypoxia and its molecular mechanism during PVR. In this study, we found using primary cultured human PASMCs that hypoxia suppressed the expression of endogenous PKGIα, which was reversed by transfection with a recombinant adenovirus containing the full-length cDNA of PKGIα (Ad-PKGIα). Ad-PKGIα transfection significantly attenuated the hypoxia-induced downregulation of the expression of smooth muscle α-actin (SM-α-actin), myosin heavy chain (MHC) and calponin in PASMCs, indicating that hypoxia-induced phenotype modulation was blocked. Furthermore, flow cytometry and (3)H-TdR incorporation demonstrated that hypoxia-induced PASMC proliferation was suppressed by upregulation of PKGIα. These results suggest that enhanced PKGIα expression inhibited hypoxia-induced PASMC phenotype modulation and that it could reverse the proliferation of PASMCs significantly. Moreover, our previous work has demonstrated that Akt protein is activated in the process of hypoxia-induced proliferation of human PASMCs. Interestingly, we found that Akt was not activated by hypoxia when PASMC phenotype modulation was blocked by Ad-PKGIα. This result suggests that blocking phenotype modulation might be a key up-stream regulatory target.

Mitochondrial and energy metabolism-related properties as novel indicators of lung cancer stem cells.

Energy metabolism is the foundation of survival for all organisms, and mitochondria are the most important energy-supplying organelles in eukaryotic cells. However, the mitochondrial and energy/metabolism-related properties of cancer stem cells (CSCs), the stem cell-like subpopulation in tumor masses, remain unknown. In our study, we compared the masses of mitochondria and mitochondrial DNA (mtDNA), the mitochondrial membrane potential (Δψm), oxygen/glucose consumption, and the concentration of reactive oxygen species (ROS) and ATP between lung CSCs (LCSCs) and non-LCSCs. In addition, the change in features during differentiation was examined. Some mitochondrial and energy metabolism-related properties, such as perinuclear mitochondrial distribution, a lower quantity of mtDNA, higher Δψm, lower oxygen/glucose consumption, and lower intracellular concentrations of ROS and ATP, can be used as indicators of LCSCs.

Heterogeneity of mitochondrial membrane potential: a novel tool to isolate and identify cancer stem cells from a tumor mass?

It is believed that cancer stem cells (CSCs) are precursors for the formation, development, and recurrence of malignant tumors. However, it has proven difficult to isolate and enrich these rare, undifferentiated cells from heterogeneous tumor masses. With some existing reports and preliminary results in mind, we hypothesized that the mitochondrial membrane potential within a tumor mass was heterogeneous and could be used as a tool to isolate and enrich CSCs.

The localization of two mimic epitopes of lipopolysaccharide binding protein and the preparation of their tandem multiple antigen peptide.

OBJECTIVE: To screen and identify two mimic epitopes in the inflammatory site of lipopolysaccharide binding protein (LBP), and to synthesize and purify their corresponding mimic epitope four branched peptide (multiple antigen peptide, MAP). METHOD: Using an anti-full length LBP monoclonal antibody as the target molecule, the amino acid sequences of the exogenous peptides were deduced by combining several different techniques including: affinity screening of the phage display peptide library, the lipopolysaccharide (LPS) binding activity assay and competitive inhibition test, cytokine production inhibition, flow cytometry, and DNA sequencing. Basic Local Alignment Search Tool (BLAST) software was used to compare the resulting peptide sequences with the primary structure sequence of the LBP molecule, and thus the amino acid sequences for two mimic inflammatory epitopes for the binding of LBP and LPS were determined. Additionally, the two target sequences were coupled, and the 9-fluorenylmethyloxycarbonyl (FMOC) solid-phase synthesis method was used to synthesize the 24aa peptide. The design program of the multiple antigen peptide (MAP) was used to couple the four tandem peptides with lysine as the core base to produce the branch like structure, and thus, the four branched peptide was synthesized and purified. RESULTS: Fourteen phage clones (C) with competitive LPS binding activity with LBP were successfully obtained. Among these, the amino acid sequences of the peptides in C2, C19, C57, C77, C85 and C91 showed a homology of more than 90% to the primary structure of LBP. However, the amino acid sequences of C29 and C90, WKAQKRFMKKSG and LKTRKLFWKYKD, respectively, did not show homology to the primary structure of LBP, which were determined to be mimic epitopes of the inflammatory sites in LBP. Further synthesis of the 24aa peptide using FMOC solid-phase synthesis and MAP modification were carried out, the four branched peptide was synthesized and purified, and the purity was found to be higher than 95%. The purified peptide was subjected to mass spectrometry analysis and amino acid analysis, and its molecular weight (3102.77 kDa) and amino acid composition were in accordance with theoretical values. CONCLUSION: The amino acid sequence for two mimic epitopes of the inflammatory site of LBP were determined to be WKAQKRFMKKSG and LKTRKLFWKYKD. The MAP was successfully prepared simultaneously and is able to be used as the core antigen protein for the formulation of vaccines. This knowledge will help in future investigations of the functional characteristics of LBP protein, and enhance exploration into new pathways for the prevention and treatment of LPS inflammatory diseases.

[Adenovirus-mediated protein-kinase-GIalpha suppresses the hypoxia-induced proliferation and phenotype-switching of pulmonary arterial smooth muscle cell].

OBJECTIVE: To observe the proliferation and phenotype-switching of pulmonary arterial smooth muscle cell (PASMC) induced by hypoxia and interfered by Ad-PKGIα. And to investigate the potential regulative role of PKGIα gene in the molecule mechanism of hypoxia pulmonary vessel remodeling (HPVR). METHODS: To establish the pure PASMC cultured by tissue-sticking methods. Semi-quantitative reverse transcription and polymerase chain reaction (RT-PCR) and Western blot were used to examine the PKGIα mRNA and protein expression after PASMC were transfected by Ad-PKG. The mRNA and protein expressive change of smooth muscle alpha actin (SM-alpha-actin) determined the degree of cell phenotype-switching. The changes of PASMC proliferation were determined by flow cytometry and ³H-TdR incorporated way. RESULTS: Ad-PKGIα could transfect into PASMC and highly express. Hypoxia down-regulated the expression of SM-alpha-actin protein (44.25 ± 5.34 in normoxia, 32.18 ± 4.19 in 12 h hypoxia condition, 21.90 ± 2.44 in 24 h hypoxia condition, P < 0.05), that could be blocked by the transfection of Ad-PKGIα. Hypoxia could push PASMC mitosis and proliferating (³H-TdR incorporated way: 7570 ± 371 in normoxia, 12,020 ± 831 in 12 h hypoxia condition, 14,924 ± 1491 in 24 h hypoxia condition, P < 0.05), that could be blocked by the transfection of Ad-PKGIα, too. CONCLUSIONS: The results suggested that PKGIα signaling pathway might play an important role in the molecule mechanism of HPVR. And PKGIα gene might be a target point of gene therapy.

Over-expression of caveolin-1 aggravate LPS-induced inflammatory response in AT-1 cells via up-regulation of cPLA2/p38 MAPK.

OBJECTIVE AND DESIGN: The aim of this study was to study the effect of caveolin-1 on the cytosolic phospholipase A2 (cPLA2), p38 mitogen-activated protein kinase (p38 MAPK) and nuclear factor kappaB (NF-kappaB) in mouse lung alveolar type-1 cells' (AT-1 cells) inflammatory response induced by LPS. MATERIALS AND METHODS: Gene clone technique was used to over-express caveolin-1 in AT-1 cells by lentivirus vector. The level of tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), cPLA2, p38 MAPK and NF-kappaB was measured by ELISA, western blotting and EMSA. TREATMENT: AT-1 cells were treated with LPS. RESULTS: Over-expression of caveolin-1 not only increased the production of pro-inflammatory cytokine TNF-alpha and IL-6, but also enhanced the expression of the cPLA2, p38 MAPK, and NF-kappaB. CONCLUSIONS: Our data demonstrated that over-expression of caveolin-1 aggravates the AT-1 injury induced by LPS, involving in modulation of the cPLA2 mediated by the cPLA2/p38 MAPK pathway.

[The effect of seawater on expression of protease-activated receptor 2 in adenocarcinoma of lung cell line A549 cells].

OBJECTIVE: To investigate the effect of seawater on expression of protease-activated receptor 2 (PAR-2) in adenocarcinoma of lung cell line A549 cells, and the inflammatory injury on A549 cells induced by seawater. METHODS: A549 cells were randomly divided into four groups: control group, 2 hours group, 4 hours group, 8 hours group, in which cells were treated with seawater for 2, 4 and 8 hours respectively. After seawater treatment, cells were collected for real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analysis to determine the expression of PAR-2 mRNA and its protein. Supernatant were collected for tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) which were determined by enzyme-linked immunosorbent essay (ELISA). RESULTS: The expression of PAR-2 mRNA and protein of A549 cells increased in a time-dependent manner after seawater treatment, significantly so after 2 hours in all groups (both P<0.05), and peaked at 4 hours after seawater treatment (1.8-fold and 2.2-fold respectively, both P<0.01), followed by a decrease though still higher than those of control group significantly (both P<0.01). TNF-alpha and IL-8 in supernatant increased significantly after seawater treatment, peaking at 2 hours after seawater treatment [(214.35+/-20.85) ng/L, (55.86+/- 5.65) ng/L ] and then followed by a slight decrease though still significantly higher than those of control group [(25.86+/-3.85) ng/L, (6.97+/-1.77) ng/L, all P<0.01]. CONCLUSION: Seawater can induce significant inflammation of A549 cells and up-regulate the expression of PAR-2 on A549 cells.

Restoration of SOCS3 suppresses human lung adenocarcinoma cell growth by downregulating activation of Erk1/2, Akt apart from STAT3.

SOCS3 is regarded as a major negative regulator of STAT3. Recent evidence indicates that SOCS3 regulates strength and duration of other signaling pathways including ras/ERK1/2/MAPK, PI3-K/Akt in non-malignant cells. The repression or silence of SOCS3 expression in a few tumor types has led to speculation that loss of SOCS3 gene is closely related to deregulation of multiple signal pathways during tumorigenesis. However, apart from STAT3, little is known in malignant cells about the mechanism by which SOCS3 modulates other intracellular signal cascades such as Erk1/2 and Akt, whose aberrant activation has been implicated in many human tumors. Expression of SOCS3 proved deficient in human lung adenocarcinoma A549 cells, and forced expression of SOCS3 resulted in growth inhibition. Growth suppression due to SOCS3 was associated with attenuated activation of Erk1/2, Akt as well as STAT3. The results suggested that SOCS3, as negative regulators of cytokine signaling, might maintain homeostasis by regulating multiple signaling pathways and reverse cell malignant behavior.

Inhibition of non-small cell lung cancer cell proliferation and tumor growth by vector-based small interfering RNAs targeting HER2/neu.

Amplification and over-expression of HER2/neu oncogene is found in diverse types of human cancers, and is closely related to tumor occurrence, metastasis, angiogenesis and chemotherapy resistance. Therapeutic agents targeting HER2/neu have been intensively addressed over the past decades. In non-small cell lung cancers (NSCLCs), the prevalence of HER2/neu activation, its role in prognosis, and its possible implications as a therapeutic target, are still to be elucidated. Here we show that the abundant or moderate over-expression of HER2/neu could be detected in both pulmonary adenocarcinoma and pulmonary large cell carcinoma cell lines. Stable knockdown of HER2/neu expression in the NSCLC cell line SPC-A-1 was achieved by vector-based small interfering RNAs (siRNAs), which consequently caused significant decrease in cell proliferation and clone forming efficiency, as well as cell cycle arrest at G(1) phase. Compared with the parental NSCLC cells, HER2/neu knockdown cells exhibited attenuated capacities in developing tumors in nude mice, and the growth tumors xenografts derived from these cells were dramatically regressed. These data provided direct evidence that HER2/neu signaling is essential for tumorigenicity of NSCLC cells, and suggested that siRNAs targeted to HER2/neu may provide a novel therapeutic strategy in the treatment of NSCLC, especially when combined with traditional therapeutics or via development of vector-based siRNAs of multiple targets that synergistically contribute to carcinogenesis, e.g. EGFR and HER2/neu.

[Small interfering RNA (siRNA) targeting vascular endothelial growth factor inhibits vascular leakage in brain of rats exposed to high altitude].

OBJECTIVE: To observe the change of expression of vascular endothelial growth factor (VEGF) and vascular leakage in the brain of rats exposed to high altitude with siRNA targeting vascular endothelial growth factor and explore the pathological mechanism and preventive approach of high altitude cerebral edema (HACE). METHODS: Fifty male Wistar rats were divided randomly into normal control group (Ncon), high altitude control group (Hcon), intraventricular normal saline control group (Scon), intraventricular siRNA group (CVI) and intravenous siRNA group (IVI). Rats in Ncon were raised normally. Rats in Hcon, Scon, CVI and IVI pretreated with intravenous injection of normal saline, intraventricular injection of normal saline, intraventricular injection of siRNA and intravenous injection of siRNA respectively were exposed to a low-pressure cabin mimicking a high altitude of 7000 m for 24 h. The ratio of dry and wet brain weight was calculated and the sodium fluorescein leakage calculated to evaluate the cerebral edema and the blood brain barrier permeability. Also the real-time quantitative RT-PCR was employed to detect the expression of VEGF mRNA and the Western blot the expression of VEGF. RESULTS: Compared with rats in NC, high altitude exposure led to a significant increase in the levels of VEGF mRNA (from 21.6 + or - 3.5 K copies/microg to 36.3 + or - 3.9 K copies/microg, P < 0.01) and protein (from 48 + or - 0.09 to 0.77 + or - 0.12, P < 0.01) in rat brain and fluorescence intensity of sodium fluorescein increased significantly (from 548 + or - 48 rfu/mg to 674 + or - 32 rfu/mg, P < 0.01). Intravenous injection of siRNA targeting to VEGF caused no significant change of expression VEGF mRNA and protein and fluorescence intensity of sodium fluorescein in rat brain (P > 0.05, respectively). While compared with rats in HC, intraventricular injection of siRNA targeting to VEGF caused the significant reduction of expression of VEGF mRNA (from 36.3 + or - 3.9 to 19.9 + or - 4.3, P < 0.01) and protein (from 0.77 + or - 0.12 to 0.44 + or - 0.13, P < 0.01) and fluorescence intensity of sodium fluorescein (from 674 + or - 32 rfu/mg to 542 + or - 77 rfu/mg, P < 0.05) in rat brain. There were no significant change in the ratio of dry and wet brain weight among five groups. CONCLUSION: VEGF may play a key role in the pathologic process of HACE. Intraventricular injection of siRNA targeting to VEGF inhibits the expression of VEGF and prevent the high altitude-induced vascular leakage. These findings might provide a basis for new preventive approaches of cerebral edema.

[The changes of PTEN/Akt1 expression and cell proliferation in pulmonary arterial smooth muscle cells induced by hypoxia in rats].

OBJECTIVE: To observe the changes of PTEN/Akt1 mRNA and protein expression level in pulmonary arterial smooth muscle cells (PASMC) induced by hypoxia in rats, and to investigate the role of PTEN/Akt1 signaling pathway in hypoxic pulmonary hypertension (HPH). METHODS: Pure PASMCs were grown and cultured from rat pulmonary arterial tissues. Semi-quantitative reverse transcription and polymerase chain reaction (RT-PCR) were used to examine PTEN and Akt1 mRNA expression after PASMCs were exposed to hypoxia for 2 h, 8 h, 12 h and 24 h respectively. PTEN/Akt1 protein expressions were determined by Western blotting. The changes of PASMC proliferation were determined by MTT and (3)H-TdR incorporation. Results were expressed as (-x) +/- s. Statistical comparisons of results were performed by t test of Excel 2003. Differences were considered significant if P < 0.05. RESULTS: PASMCs were induced to keep proliferating by hypoxia. The value of (3)H-TdR was 0.37 +/- 0.06 under normoxia, but was increased with prolonged exposure to hypoxia, reaching 0.70 +/- 0.10 at 12 h (t = 14.29, P < 0.01), being significantly different compared to the normoxia group. The value of MTT was 8374 +/- 545 under normoxia, but was increased by exposure to hypoxia, reaching 11 208 +/- 679 at 24 h (t = 19.56, P < 0.01), being significantly different compared to the normoxia group. The mRNA and protein of PTEN/Akt1 were detectable in all the groups. The values of mRNA, total protein and phosphorylated protein of Akt1 were 0.76 +/- 0.09, 25 +/- 6, 48 +/- 8 respectively in the normoxia group. After exposure to hypoxia, the values were 1.05 +/- 0.09, 41 +/- 7, 79 +/- 14 respectively at 8 h, being significantly different compared to the normoxia group (t = 168.00, 58.54, 8.31, P < 0.01 and P < 0.05), but the values decreased thereafter and returned to the level comparable to the normoxia group at 24 h. The values of mRNA, phosphorylated protein of PTEN were 0.25 +/- 0.06, and 98 +/- 8 respectively in the normoxia group, but were increased after exposure to hypoxia, reaching 0.38 +/- 0.05, and 232 +/- 12 respectively at 24 h, being significantly different compared to the normoxia group (t = 22.04, 50.46, all P < 0.01). CONCLUSION: The results suggested that PTEN/Akt1 signaling pathway might play an important role in hypoxic pulmonary hypertension.

[The protective effects and mechanisms of peroxisome proliferator-activated receptor-gamma agonist in rats with acute lung injury].

OBJECTIVE: To observe if peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist (troglitazone) was able to alleviate lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats, and explore the underlying mechanisms. METHODS: Seventy-two wistar rats were randomized into the the following groups, the LPS groups (32 rats), and the troglitazone intervention groups (T group, 32 rats) and a control group (8 rats). T groups and LPS groups were divided into 1, 2, 4, 8 h subgroups (n = 8 each) according to the experimental protocol. LPS (5 mg/kg) was administered through the vein in the LPS groups. In the T groups, 15 min after LPS injecting, troglitazone was administrated (3 mg/kg) through the vein. PaO2, myeloperoxidase activity (MPO), lung tissue histopathological changes were observed. Expressions of PPAR-gamma mRNA and TNF-alpha mRNA were assayed by RT-PCR, TNF-alpha levels measured with ELISA, expression of PPAR-gamma protein in lung tissue detected by immunohistochemistry method, and expression of NF-kappaB P65 protein assayed by Western Blot. The data were expressed as mean +/- SD and analyzed with SPSS 10.0 software. RESULTS: PaO2 in 1, 2, 4, and 8 h groups were (85 +/- 10), (80 +/- 10), (81 +/- 10), (82 +/- 13) mm Hg (1 mmHg =0.133 kPa) in the T groups, (75 +/- 11), (69 +/- 12), (63 +/- 11), (71 +/- 13) mm Hg in the LPS groups, respectively, the difference being significant between groups (F = 4.32, P < 0.05). MPO activity in 2, 4 and 8 h groups were (10.6 +/- 1.2), (14.1 +/- 2.1), (11.1 +/- 1.8) U/g in the LPS groups, (8.2 +/- 0.8), (9.2 +/- 0.9), (8.8 +/- 0.7) U/g in the T groups, and comparison between groups showed statistical significance (F = 14.99, P <0.05). TNF-alpha mRNA expression (A) in 1 h group and 2 h group were 0.68 +/- 0.07, 0.92 +/- 0.05 in the LPS groups and 0.39 +/- 0.07, 0.50 +/- 0.09 in the T groups, and comparison between groups showed statistical significance (q = 3.09, 3.99, P <0.05). TNF-alpha levels in 1 h group and 2 h group in lung homogenate and plasma were (340 +/- 33), (757 +/- 47), (12.3 +/- 1.8), (54.7 +/- 6.6) ng/L in LPS groups, (306 +/- 30), (685 +/- 47), (10.0 +/- 1.7), (46.8 +/- 5.9) ng/L in T groups, the difference between groups being significant(q =3.92, 4.71, 4.81, 5.17, all P<0.05). PPAR-gamma mRNA expression (A) in 1 h, 2 h and 4 h groups were 0.36 +/- 0.05, 0.25 +/- 0.04, 0.30 +/- 0.05 in the LPS groups, 0.39 +/- 0.02, 0.44 +/- 0.05, 0.46 +/- 0.04 in the T groups, the difference between groups being significant (q =6.13, 5.69, 3.72, all P <0.05). NF-kappaB P65 translocated from plasma to nucleus in 1 h and 8 h group; the A values were 0.81 +/- 0.14, 1.91 +/- 0.16, 0.33 +/- 0.06, 2.01 +/- 0.18 in the LPS groups and 1.14 +/- 0.15, 1.06 +/- 0.21, 0.81 +/- 0.14, 1.03 +/- 0.18 in the T groups, comparison between groups showed statistical difference (q = 3.29, 6.25, 5.59, 6.81, all P <0.05). CONCLUSION: PPAR-gamma agonist (troglitazone) decreased the expression levels of inflammatory mediators such as TNF-alpha, reduced infiltration and activation of inflammatory cells in lung tissues, and alleviated LPS-induced through PPAR-gamma upregulation and inhibition of NF-kappaB activity.