The tRNA-GCN2-FBXO22-axis-mediated mTOR ubiquitination senses amino acid insufficiency.

Mammalian target of rapamycin complex 1 (mTORC1) monitors cellular amino acid changes for function, but the molecular mediators of this process remain to be fully defined. Here, we report that depletion of cellular amino acids, either alone or in combination, leads to the ubiquitination of mTOR, which inhibits mTORC1 kinase activity by preventing substrate recruitment. Mechanistically, amino acid depletion causes accumulation of uncharged tRNAs, thereby stimulating GCN2 to phosphorylate FBXO22, which in turn accrues in the cytoplasm and ubiquitinates mTOR at Lys2066 in a K27-linked manner. Accordingly, mutation of mTOR Lys2066 abolished mTOR ubiquitination in response to amino acid depletion, rendering mTOR insensitive to amino acid starvation both in vitro and in vivo. Collectively, these data reveal a novel mechanism of amino acid sensing by mTORC1 via a previously unknown GCN2-FBXO22-mTOR pathway that is uniquely controlled by uncharged tRNAs.

Furin extracellularly cleaves secreted PTENα/ß to generate C-terminal fragment with a tumor-suppressive role.

PTENα and PTENß (PTENα/ß), two long translational variants of phosphatase and tensin homolog on chromosome 10 (PTEN), exert distinct roles from canonical PTEN, including promoting carcinogenesis and accelerating immune-resistant cancer progression. However, their roles in carcinogenesis remain greatly unknown. Herein, we report that, after secreting into the extracellular space, PTENα/ß proteins are efficiently cleaved into a short N-terminal and a long C-terminal fragment by the proprotein convertase Furin at a polyarginine stretch in their N-terminal extensions. Although secreted PTENα/ß and their cleaved fragment cannot enter cells, treatment of the purified C-terminal fragment but not cleavage-resistant mutants of PTENα exerts a tumor-suppressive role in vivo. As a result, overexpression of cleavage-resistant PTENα mutants manifest a tumor-promoting role more profound than that of wild-type PTENα. In line with these, the C-terminal fragment is significantly downregulated in liver cancer tissues compared to paired normal tissues, which is consistent with the downregulated expression of Furin. Collectively, we show that extracellular PTENα/ß present opposite effects on carcinogenesis from intracellular PTENα/ß, and propose that the tumor-suppressive C-terminal fragment of PTENα/ß might be used as exogenous agent to treat cancer.

Prognostic factors and survival outcome of primary pulmonary acinar cell carcinoma.

PURPOSE: The objective of our study was to investigate the epidemiologic characteristics and prognostic factors in patients with pulmonary acinar cell carcinoma (PACC). METHODS: PACC patients diagnosed between 1975 and 2016 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The trend in PACC incidence was assessed using joinpoint regression software. Overall survival (OS) and disease-specific survival (DSS) were evaluated using the Kaplan-Meier method and log-rank test. Univariate and multivariate Cox regression analysis was performed to identify the independent prognostic factors for OS and DSS. Nomograms to predict survival possibilities were constructed based on the identified independent prognostic factors. RESULTS: A total of 2918 patients were identified with PACC. The mean age was 65.2 ± 8.95 years with a female to male of 1.6:1. The incidence of PACC steadily increased by an annual percentage change (APC) of 3.2% (95% CI 2.1-4.4, p < 0.05). Multivariate Cox regression analysis revealed that age, gender, race, stage, grade, tumor size, number of positive lymph nodes, surgery, and chemotherapy were independent prognostic factors for survival. Nomograms specifically for PACC were constructed to predict 1- and 5-year OS and DSS possibility, respectively. The concordance index (C-index) and calibration plots showed the established nomograms had robust and accurate performance. CONCLUSION: PACC was rare but the incidence has been steadily increasing over the past four decades. Survival has improved in recent years. Surgery or chemotherapy could provide better OS and DSS. The established nomograms specifically for PACC were robust and accurate in predicting 1- and 5-year OS and DSS.

Design, synthesis and evaluation of halogenated furanone derivatives as quorum sensing inhibitors in Pseudomonas aeruginosa.

The biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) is regulated by a phenomenon of quorum sensing (QS). With 5-hydroxyl-3,4-halogenated-5H-furan-2-ones as beginning, analogs bearing alkyl chains, vinyl bromide, or aromatic rings were designed and synthesized. The minimum inhibitory concentration (MIC) of the compounds against P. aeruginosa was assayed and the biofilm inhibition ratio was determined at different concentrations lower than the MIC. C-5 aromatic substituted furanones showed remarkable biofilm formation as well as inhibition of virulence factor production in P. aeruginosa. Fluorescence report analysis identified the QS regulatory mechanism of the most active compound 29. This study provides us a novel candidate for combating drug resistant bacteria strains by merely inhibiting biofilm formation. Without suppressing the regular life cycle of the bacteria, bacterial resistance mechanisms may not be activated.

Logistic regression analysis of clinical and computed tomography features of pulmonary abscesses and risk factors for pulmonary abscess-related empyema.

OBJECTIVES: This study was conducted to investigate the risk factors for pulmonary abscess-related empyema by investigating the clinical characteristics and chest computed tomography imaging features of patients with pulmonary abscesses. METHODS: We retrospectively analyzed the chest computed tomography findings and clinical features of 101 cases of pulmonary abscess, including 25 cases with empyema (the experimental group) and 76 cases with no empyema (the control group). The potential risk factors for pulmonary abscess-related empyema were compared between the groups by using univariate and multivariate logistic regression analyses. RESULTS: The incidence of pulmonary abscess-related empyema was 24.8% (25/101). Univariate analysis showed that male gender, diabetes, pleuritic symptoms, white blood cells >10×109/L, albumin level <25 g/L, and positive sputum cultures were potential clinical-related risk factors and that an abscess >5 cm in diameter and transpulmonary fissure abscesses were potential computed tomography imaging-related risk factors for pulmonary abscess-related empyema. Multivariate logistic regression analysis showed that transpulmonary fissure abscesses (odds ratio=9.102, p=0.003), diabetes (odds ratio=9.066, p=0.003), an abscess >5 cm in diameter (odds ratio=8.998, p=0.002), and pleuritic symptoms (odds ratio=5.395, p=0.015) were independent risk factors for pulmonary abscess-related empyema. CONCLUSIONS: Transpulmonary fissure abscesses, diabetes, giant pulmonary abscesses, and pleuritic symptoms increased the risk of empyema among patients with pulmonary abscesses.

Logistic regression analysis of clinical and computed tomography features of pulmonary abscesses and risk factors for pulmonary abscess-related empyema

OBJECTIVES: This study was conducted to investigate the risk factors for pulmonary abscess-related empyema by investigating the clinical characteristics and chest computed tomography imaging features of patients with pulmonary abscesses. METHODS: We retrospectively analyzed the chest computed tomography findings and clinical features of 101 cases of pulmonary abscess, including 25 cases with empyema (the experimental group) and 76 cases with no empyema (the control group). The potential risk factors for pulmonary abscess-related empyema were compared between the groups by using univariate and multivariate logistic regression analyses. RESULTS: The incidence of pulmonary abscess-related empyema was 24.8% (25/101). Univariate analysis showed that male gender, diabetes, pleuritic symptoms, white blood cells >10×109/L, albumin level <25 g/L, and positive sputum cultures were potential clinical-related risk factors and that an abscess >5 cm in diameter and transpulmonary fissure abscesses were potential computed tomography imaging-related risk factors for pulmonary abscess-related empyema. Multivariate logistic regression analysis showed that transpulmonary fissure abscesses (odds ratio=9.102, p=0.003), diabetes (odds ratio=9.066, p=0.003), an abscess >5 cm in diameter (odds ratio=8.998, p=0.002), and pleuritic symptoms (odds ratio=5.395, p=0.015) were independent risk factors for pulmonary abscess-related empyema. CONCLUSIONS: Transpulmonary fissure abscesses, diabetes, giant pulmonary abscesses, and pleuritic symptoms increased the risk of empyema among patients with pulmonary abscesses.

Molecular Analysis-Based Genetic Characterization of a Cohort of Patients with Duchenne and Becker Muscular Dystrophy in Eastern China.

BACKGROUND: Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are common X-linked recessive neuromuscular disorders caused by mutations in dystrophin gene. Multiplex polymerase chain reaction (multiplex PCR) and multiplex ligation-dependent probe amplification (MLPA) are the most common methods for detecting dystrophin gene mutations. This study aimed to contrast the two methods and discern the genetic characterization of patients with DMD/BMD in Eastern China. METHODS: We collected 121 probands, 64 mothers of probands, and 15 fetuses in our study. The dystrophin gene was detected by multiplex PCR primarily in 28 probands, and MLPA was used in multiplex PCR-negative cases subsequently. The dystrophin gene of the remaining 93 probands and 62 female potential carriers was tested by MLPA directly. In fetuses, multiplex PCR and MLPA were performed on 4 fetuses and 10 fetuses, respectively. In addition, sequencing was also performed in 4 probands with negative MLPA. RESULTS: We found that 61.98% of the subjects had genetic mutations including deletions (50.41%) and duplications (11.57%). There were 43.75% of mothers as carriers of the mutation. In 15 fetuses, 2 out of 7 male fetuses were found to be unhealthy and 2 out of 8 female fetuses were found to be carriers. Exons 3-26 and 45-52 have the maximum frequency in mutation regions. In the frequency of exons individually, exon 47 and exon 50 were the most common in deleted regions and exons 5, 6, and 7 were found most frequently in duplicated regions. CONCLUSIONS: MLPA has better productivity and sensitivity than multiplex PCR. Prenatal diagnosis should be applied in DMD high-risk fetuses to reduce the disease incidence. Furthermore, it is the responsibility of physicians to inform female carriers the importance of prenatal diagnosis.

Krüppel-like factor 17 inhibits urokinase plasminogen activator gene expression to suppress cell invasion through the Src/p38/ MAPK signaling pathway in human lung adenocarcionma.

Krüppel-like factor 17 (KLF17) has been reported to be involved in invasion and metastasis suppression in lung cancer, but the molecular mechanisms underlying the anti-invasion and anti-metastasis roles of KLF17 in lung cancer are not fully illustrated. Here, we showed that KLF17 inhibited the invasion of A549 and H322 cells; the anti-invasion effect of KLF17 was associated with the suppression of urokinase plasminogen activator (uPA/PLAU) expression. KLF17 can bind with the promoter of uPA and inhibit its expression. Enforced expression of uPA abrogated the anti-invasion effect of KLF17 in A549 and H322 cells. In addition, immunohistochemistry staining showed that the protein expression of KLF17 was negatively correlated with that of uPA in archived samples from patients with lymph node metastasis of lung adenocarcinoma (rho = -0.62, P = 0.01). The mutually exclusive expression of KLF17 with uPA could predict lymph node metastasis for lung adenocarcinoma (AUC = 0.758, P = 0.005). Enforced expression of KLF17 inhibited the expression of phosphorylated Src and phosphorylated p38/MAPK in A549 and H322 cells. The invasiveness of the cells were suppressed by treating with sb203580 (p38/MAPK inhibitor) or HY-13805 (PP2, Src inhibitor). furthermore, p38/MAPK inhibition could block the KLF17-induced reduction of p-p38/MAPK and uPA, and Src inhibition enhanced the KLF17-induced suppression of p-Src and uPA in A549 and H322 cells. In conclusion, our study indicated that KLF17 suppressed the uPA-mediated invasion of lung adenocarcinoma. The Src and p38/MAPK signaling pathways were suggested as mediators of KLF17-induced uPA inhibition, thus providing evidence that KLF17 might be a potential anti-invasion candidate for lung adenocarcinoma.

Molecular cloning, characterization and mRNA expression of selenium-binding protein in abalone (Haliotis discus hannai Ino): Response to dietary selenium, iron and zinc.

Selenium-binding protein (SEBP) is believed to play crucial role in controlling the oxidation/reduction in the physiological processes. In this study, the cDNA of selenium-binding protein from abalone Haliotis discus hannai Ino (HdhSEBP) was cloned by homology cloning and rapid amplification of cDNA ends (RACE) technique. The full length of HdhSEBP cDNA was 2071 bp, consisting of a 5' untranslated region (UTR) of 55 bp, a 3' UTR of 522 bp, and an open reading frame (ORF) of 1494 bp. The deduced protein has 497 amino acid residues with a calculated molecular mass of 55.6 kDa and a predicted isoelectric point of 5.47. BLAST analysis reveals that HdhSEBP shares high identities with other known SEBPs from mammal, bird, fish and mollusk, etc. The mRNA expression patterns of HdhSEBP in hepatopancreas and haemocytes were measured by real-time PCR in abalone fed with nine different diets containing graded levels of selenium (0, 1 and 50 mg kg(-1)), iron (0, 65 and 1300 mg kg(-1)) and zinc (0, 35 and 700 mg kg(-1)) for 20 weeks, respectively. The results showed that the expression of the HdhSEBP mRNA increased and reached the maximum at optimal dietary selenium (1 mg kg(-1)), iron (65 mg kg(-1)) and zinc (35 mg kg(-1)), respectively. Deficient or excessive level of dietary selenium, iron or zinc, respectively, leaded to significant depression of HdhSEBP mRNA. It is concluded that the expression levels of HdhSEBP are affected by dietary selenium, iron or zinc.

[Sealing of tracheoesophageal fistula using Sigma covered mental stents].

OBJECTIVE: To explore the possibilities and efficiency of Sigma covered stents for the treatment of tracheoesophageal fistula (TEF). METHODS: Between 2006 and 2009, 10 Sigma covered mental stents had been placed by guidance of bronchoscopy and/or fluoroscopy in 8 patients with 9 tracheoesophageal fistulas. Among them, 7 fistulas were caused by cancer and 2 by mechanical damage. Seven fistulas were located in lower part of trachea and 1 each in the middle and upper parts. RESULTS: Six Y-shaped, 2 L-shaped and 2 I-shaped stents were placed respectively in 8 patients with 9 TEFs. All the TEFs were effectively sealed by the stents except for 1 massive lower and 1 upper fistulas. One mechanical fistula was cured within 1 year of stent placement. The mean survival period of all patients was 8 months. CONCLUSION: By sealing the fistula with a Sigma covered stent, severe respiratory infection may be successfully controlled in patients with TEFs with a major improvement of quality of life.

The antithrombotic action of propylene glycol mannite sulfate (PGMS).

In order to reveal the antithrombotic mechanism of propylene glycol mannite sulfate (PGMS) on gene level and explore the correlation between PGMS and fibrinolytic system, the urokinase-type plasminogen activator (uPA) mRNA expression and uPA activity were detected in vitro and in vivo with semi-quantitative reverse transcription (RT)-PCR and chromogenic method. The results showed that PGMS was able to increase uPA activity in dosage-dependent manner in rat plasma, which resulted in the increase of rat fibrinolytic activity. The change of rat uPA mRNA expression with PGMS was similar to that of uPA activity. The results of experiments with cultured cells were similar to those results of experiments in vivo. The uPA mRNA expression and activities of cultured cells showed increases with PGMS in a concentration-dependent manner. All of these results indicated that PGMS may induce the expression of uPA mRNA. The increase of uPA mRNA expression may therefore reflect, in part, an increase in the stability of uPA mRNA and/or processing of nuclear uPA transcription, which, in turn, may increase the uPA activity in rat plasma and trigger the fibrinolytic system.

[The relationship between leukemia inhibitory factor and neurokinin receptors in a rat model of asthma].

OBJECTIVE: To study the expression of leukemia inhibitory factor (LIF) and neurokinin receptors (NKR) in the lungs of asthmatic rats, and to evaluate the role of LIF in airway neurogenic inflammation. METHODS: Twenty-four Wistar rats were randomly divided into a control group (group A, n = 8), an asthma group (group B, n = 8) and a dexamethasone treated group (group C, n = 8). The rat asthmatic model was made by intraperitoneal injection and nebulized aspiration of ovalbumin (OVA) at the concentrations of 10% and 1% respectively. Expression levels of lung LIF, NK-1R and NK-2R were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot two weeks after challenge, and the localization of NK-1R was determined by immunohistochemistry. RESULTS: After challenge, the expressions of lung LIF mRNA in group A, B and C were 0.240 +/- 0.020, 0.510 +/- 0.130, 0.180 +/- 0.050, and protein levels were 23 110 +/- 8 018, 40 832 +/- 12 964, 16 160 +/- 2 108 respectively. The expressions of lung NK-1R mRNA in group A, B and C were 0.240 +/- 0.020, 1.040 +/- 0.480, 0.170 +/- 0.040, and protein levels were 16 538 +/- 4 342, 32 292 +/- 4 564, 15 018 +/- 1 488 respectively. The mRNA and protein levels of LIF and NK-1R in group B were significantly elevated as compared with group A and C (all P < 0.01). The expressions of lung NK-2R mRNA in group A, B and C were 0.240 +/- 0.040, 0.200 +/- 0.030 and 0.210 +/- 0.040, and no difference was found among three groups (all P > 0.05). In group B, there was a positive correlation between LIF and NK-1R at mRNA (r = 0.850, P < 0.01) and protein (r = 0.868, P < 0.01) levels respectively. NK-1R immunoreactivity was observed primarily in bronchial epithelial cells. CONCLUSION: LIF and NK-1R were excessively expressed and closely correlated in lungs of the rat asthmatic model, suggesting that LIF may be involved in modulating airway neurogenic inflammation.

[Clinical analysis of gastroesophageal reflux induced cough].

OBJECTIVE: To investigate the clinical features, diagnosis and management of gastroesophageal reflux induced cough (GERC). METHODS: The continuous ambulatory esophageal pH measurement was performed for 24 hour in 41 cases with chronic cough who had normal chest roentgenographic presentation, negative histamine provocation test and no abnormality of nasal cavity. The symptom association probability (SAP) was adopted to analyze the correlation of cough with gastroesophageal reflux. The anti-reflux treatment was given for 12 weeks to those patients with Demeester score >or= 14.72 and/or SAP >or= 75%. RESULTS: Twenty six out of 41 cases were diagnosed as patients with gastroesophageal reflux. The cough was completely cured in 12 cases after antireflux treatment. The SAP of cough in this cured group (proximal probe 0.75 +/- 0.21, distal probe 0.91 +/- 0.12, respectively) was significantly higher than that of patients who failed in response to antireflux treatment (proximal probe 0.36 +/- 0.31, distal probe 0.47 +/- 0.30, respectively, P < 0.05). CONCLUSION: The gastroesophageal reflux may be an independent factor which could induce chronic cough. Not only the frequency and severity of gastroesophageal reflux but also the SAP were helpful in making the diagnosis of GERC. Satisfied effect was achieved after sufficient anti-reflux treatment in patients with GERC.

[Clinical feature and airway inflammation in eosinophilic bronchitis].

OBJECTIVE: To study the clinical features and airway inflammation in eosinophilic bronchitis (EB) and the treatment outcomes. METHODS: Irwin's anatomic protocol for diagnosing chronic cough was used in 86 patients with chronic cough, and induced sputum by hypertonic saline aerosol inhalation was performed. Differential cell counts were performed in induced sputum, and eosinophilic cationic protein (ECP) was measured with fluoroimmunoassay, while interleukin-8 (IL-8) was measured with enzyme-linked absorbed immunoassay. EB was diagnosed according to Gibson's criteria and treated with inhaled budesonide 200 - 400 micro g twice daily for four weeks, and in some patients oral prednisone 10 - 15 mg/d or methyl-prednisone 8 - 12 mg/d was given for one week. RESULTS: 13 (15%) out of 86 patients with chronic cough were diagnosed as having EB. Dry cough was the major compliant and all had normal lung function with negative histamine provocation test. The Eos count was 0.1862 +/- 0.1632 and the concentration of ECP (2.53 +/- 2.07) mg/L in induced sputum were significant higher in patients with EB as compared with those normal subjects (P < 0.01). The cough disappeared in all patients at the end of one week of inhaled or orally administered corticosteroids. CONCLUSION: EB, an eosinophilic airway inflammation, is one of important causes of chronic cough and responds well to corticosteroid therapy.

[Etiological diagnosis of chronic cough with unknown causes].

OBJECTIVE: To explore the spectrum and frequency of causes for chronic cough in Chinese patients. METHODS: 86 patients with chronic cough were enrolled in the study. The diagnostic procedure was based on the anatomical protocol for diagnosing chronic cough designed by Irwin, and additional cytological assay was performed for sputum induced by hypertonic saline aerosol inhalation. The efficacy of therapy specific to the diagnosis was evaluated. RESULTS: Definite diagnosis was made in 77 (89.5%) out of the 86 patients with chronic cough. The most common causes included cough variant asthma (CVA) (24/86, 27.9%), postnasal drip syndrome (PNDs) (22/86, 25.6%), eosinophilic bronchitis (EB) (13/86, 15.1%), and gastroesophageal reflux (GER) (12/86, 14.0%). After active management based on the diagnosis, cough improved in 72 patients (93.5%). CONCLUSIONS: In addition to CVA, PNDs and GER, eosinophilic bronchitis is also an important cause of chronic cough. A positive response to the specific therapy is essential to a definite diagnosis.