Role of TRPA1 in Tissue Damage and Kidney Disease.

TRPA1, a nonselective cation channel, is expressed in sensory afferent that innervates peripheral targets. Neuronal TRPA1 can promote tissue repair, remove harmful stimuli and induce protective responses via the release of neuropeptides after the activation of the channel by chemical, exogenous, or endogenous irritants in the injured tissue. However, chronic inflammation after repeated noxious stimuli may result in the development of several diseases. In addition to sensory neurons, TRPA1, activated by inflammatory agents from some non-neuronal cells in the injured area or disease, might promote or protect disease progression. Therefore, TRPA1 works as a molecular sentinel of tissue damage or as an inflammation gatekeeper. Most kidney damage cases are associated with inflammation. In this review, we summarised the role of TRPA1 in neurogenic or non-neurogenic inflammation and in kidney disease, especially the non-neuronal TRPA1. In in vivo animal studies, TRPA1 prevented sepsis-induced or Ang-II-induced and ischemia-reperfusion renal injury by maintaining mitochondrial haemostasis or via the downregulation of macrophage-mediated inflammation, respectively. Renal tubular epithelial TRPA1 acts as an oxidative stress sensor to mediate hypoxia-reoxygenation injury in vitro and ischaemia-reperfusion-induced kidney injury in vivo through MAPKs/NF-kB signalling. Acute kidney injury (AKI) patients with high renal tubular TRPA1 expression had low complete renal function recovery. In renal disease, TPRA1 plays different roles in different cell types accordingly. These findings depict the important role of TRPA1 and warrant further investigation.

Renal Tubular Epithelial TRPA1 Acts as An Oxidative Stress Sensor to Mediate Ischemia-Reperfusion-Induced Kidney Injury through MAPKs/NF-κB Signaling.

Oxidative stress and inflammation play important roles in the pathophysiology of acute kidney injury (AKI). Transient receptor potential ankyrin 1 (TRPA1) is a Ca2+-permeable ion channel that is sensitive to reactive oxygen species (ROS). The role of TRPA1 in AKI remains unclear. In this study, we used human and animal studies to assess the role of renal TRPA1 in AKI and to explore the regulatory mechanism of renal TRPA1 in inflammation via in vitro experiments. TRPA1 expression increased in the renal tubular epithelia of patients with AKI. The severity of tubular injury correlated well with tubular TRPA1 or 8-hydroxy-2'-deoxyguanosine expression. In an animal model, renal ischemia-reperfusion injury (IR) increased tubular TRPA1 expression in wild-type (WT) mice. Trpa1-/- mice displayed less IR-induced tubular injury, oxidative stress, inflammation, and dysfunction in kidneys compared with WT mice. In the in vitro model, TRPA1 expression increased in renal tubular cells under hypoxia-reoxygenation injury (H/R) conditions. We demonstrated that H/R evoked a ROS-dependent TRPA1 activation, which elevated intracellular Ca2+ level, increased NADPH oxidase activity, activated MAPK/NF-κB signaling, and increased IL-8. Renal tubular TRPA1 may serve as an oxidative stress sensor and a crucial regulator in the activation of signaling pathways and promote the subsequent transcriptional regulation of IL-8. These actions might be evident in mice with IR or patients with AKI.

TLC388 Induces DNA Damage and G2 Phase Cell Cycle Arrest in Human Non-Small Cell Lung Cancer Cells.

TLC388, a camptothecin-derivative targeting topoisomerase I, is a potential anticancer drug. In this study, its effect on A549 and H838 human non-small cell lung cancer (NSCLC) cells was investigated. Cell viability and proliferation were determined by thiazolyl blue tetrazolium bromide and clonogenic assays, respectively, and cell cycle analysis and detection of phosphorylated histone H3 (Ser10) were performed by flow cytometry. γ-H2AX protein; G2/M phase-associated molecules ataxia-telangiectasia mutated (ATM), CHK1, CHK2, CDC25C, CDC2, and cyclin B1; and apoptosis were assessed with immunofluorescence staining, immunoblotting, and an annexin V assay, respectively. The effect of co-treatment with CHIR124 (a checkpoint kinase 1 [CHK1] inhibitor) was also studied. TLC388 decreased the viability and proliferation of cells of both NSCLC lines in a dose-dependent manner. TLC388 inhibited the viability of NSCLC cell lines with an estimated concentration of 50% inhibition (IC50), which was 4.4 and 4.1 µM for A549 and H838 cells, respectively, after 24 hours. Moreover, it resulted in the accumulation of cells at the G2/M phase and increased γ-H2AX levels in A549 cells. Levels of the G2 phase-related molecules phosphorylated ATM, CHK1, CHK2, CDC25C, and cyclin B1 were increased in TLC388-treated cells. CHIR124 enhanced the cytotoxicity of TLC388 toward A549 and H838 cells and induced apoptosis of the former. TLC388 inhibits NSCLC cell growth by inflicting DNA damage and activating G2/M checkpoint proteins that trigger G2 phase cell cycle arrest to enable DNA repair. CHIR124 enhanced the cytotoxic effect of TLC388 and induced apoptosis.

Opposite effects of statins on the risk of tuberculosis and herpes zoster in patients with diabetes: A population-based cohort study.

It remains uncertain whether statin use is associated with the risks of tuberculosis (TB) and herpes zoster in patients with type 2 diabetes. This study aims to assess the effects of statins vs nonstatin lipid-lowering agents on the risk of these infectious diseases in patients with diabetes. METHODS: Participants in the Taiwan National Health Insurance Research Database diagnosed with type 2 diabetes in 2001-2013 were classified as statin users, nonstatin users and lipid-lowering drug-free groups. Participants were observed for incident TB and herpes zoster from diabetes diagnosis until treatment crossover or December 2013. Statin user and nonstatin user were the time-dependent variables in Cox regression analysis. RESULTS: Over 240 782 person-years of observation, statin users (n = 17 696) were associated with a lower TB risk than nonstatin users (n = 5327) and the drug-free group (n = 22 316) (adjusted hazard ratio [aHR]: 0.66; 95% confidence interval [CI]: 0.44-0.99 and aHR: 0.57; 95% CI: 0.44-0.73). Compared with nonstatin users, statin users showed a dose-dependent association with TB risk (low-potency statin users, aHR: 0.692; 95% CI: 0.455-1.053; high-potency users, aHR: 0.491; 95% CI: 0.241-0.999). Statin users presented with a higher risk of herpes zoster than nonstatin users and the drug-free group (aHR: 1.23; 95% CI: 1.01-1.50 and aHR: 1.20; 95% CI: 1.09-1.33). The risks of TB and herpes zoster were not statistically different between nonstatin users and the drug-free group. CONCLUSION: Compared with nonstatin drugs, statin use was specifically associated with a decreased risk of TB but a moderately increased risk of herpes zoster in this cohort study.

Measuring (1,3)-ß-D-glucan in tracheal aspirate, bronchoalveolar lavage fluid, and serum for detection of suspected Candida pneumonia in immunocompromised and critically ill patients: a prospective observational study.

BACKGROUND: While Candida pneumonia is life-threatening, biomarker measurements to early detect suspected Candida pneumonia are lacking. This study compared the diagnostic values of measuring levels of (1, 3)-ß-D-glucan in endotracheal aspirate, bronchoalveolar lavage fluid, and serum to detect suspected Candida pneumonia in immunocompromised and critically ill patients. METHODS: This prospective, observational study enrolled immunocompromised, critically ill, and ventilated patients with suspected fungal pneumonia in mixed intensive care units from November 2010 to October 2011. Patients with D-glucan confounding factors or other fungal infection were excluded. Endotracheal aspirate, bronchoalveolar lavage fluid and serum were collected from each patient to perform a fungal smear, culture, and D-glucan assay. RESULTS: After screening 166 patients, 31 patients completed the study and were categorized into non-Candida pneumonia/non-candidemia (n = 18), suspected Candida pneumonia (n = 9), and non-Candida pneumonia/candidemia groups (n = 4). D-glucan levels in endotracheal aspirate or bronchoalveolar lavage were highest in suspected Candida pneumonia, while the serum D-glucan level was highest in non-Candida pneumonia/candidemia. In all patients, the D-glucan value in endotracheal aspirate was positively correlated with that in bronchoalveolar lavage fluid. For the detection of suspected Candida pneumonia, the predictive performance (sensitivity/specificity/D-glucan cutoff [pg/ml]) of D-glucan in endotracheal aspirate and bronchoalveolar lavage fluid was 67%/82%/120 and 89%/86%/130, respectively, accounting for areas under the receiver operating characteristic curve of 0.833 and 0.939 (both P < 0.05), respectively. Measuring serum D-glucan was of no diagnostic value (area under curve =0.510, P = 0.931) for the detection of suspected Candida pneumonia in the absence of concurrent candidemia. CONCLUSIONS: D-glucan levels in both endotracheal aspirate and bronchoalveolar lavage, but not in serum, provide good diagnostic values to detect suspected Candida pneumonia and to serve as potential biomarkers for early detection in this patient population.

Additive effect of congenital heart disease and early developmental disorders on attention-deficit/hyperactivity disorder and autism spectrum disorder: a nationwide population-based longitudinal study.

In this retrospective nationwide population-based case-control study, we investigated the impact of congenital heart disease (CHD) on the development of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), which remains unclear. Children aged <18 years that were diagnosed with CHD (n = 3552) between January 1, 1997 and December 31, 2009 were identified from the National Health Insurance Research Database in Taiwan. Non-CHD controls (n = 14,208) matched for age and sex (1:4) were selected from the same dataset. All subjects were observed until December 31, 2011 or their death. Comorbid perinatal conditions and early developmental disorders (EDD) that were diagnosed before ADHD and ASD diagnosis were also analyzed. The incidence rates of perinatal comorbidities, EDD, ADHD, and ASD were higher in the CHD group than in the control group. Multivariate Cox regression analysis revealed that the CHD group had an increased risk of developing ADHD (adjusted hazard ratio [aHR] 2.52, 95% confidence interval CI 1.96-3.25) and ASD (aHR 1.97, 95% CI 1.11-3.52) after adjusting for confounding comorbidities. EDD, but not perinatal comorbidities were also independent risk factors for ADHD and ASD after adjustment. Subgroup analysis indicated that the risk for ADHD (HR 16.59, 95% CI 12.17-22.60) and ASD (HR 80.68, 95% CI 39.96-176.12) was greatly increased in CHD subjects with EDD than in non-CHD subjects without EDD. These findings suggested that CHD at birth and EDD during early childhood were two independent risk factors for ADHD and ASD and that concurrent CHD and EDD might additively increase these risks.

Effects of Surfactant Lavage Combined With Intratracheal Budesonide Instillation on Meconium-Injured Piglet Lungs.

OBJECTIVES: To evaluate the combined effects of surfactant lavage and intratracheally instillation of budesonide on meconium-injured piglet lungs. DESIGN: A prospective, randomized, animal model study. SETTING: An experimental laboratory. SUBJECTS: Twenty-four anesthetized and mechanically ventilated newborn piglets. INTERVENTIONS: Human meconium slurry was intratracheally instilled into piglet lungs to induce lung injury. The injured piglets were randomly assigned to either the sham treatment group (control) or one of the three therapeutic groups: the intratracheally instilled budesonide (Bud) group, the bronchoalveolar lavage with diluted surfactant (dsBAL) group, and the combination therapy of Bud and dsBAL (dsBAL + Bud) group. MEASUREMENTS AND MAIN RESULTS: Cardiopulmonary profiles were measured hourly. Proinflammatory cytokine (interleukin-1ß, interleukin-6, and interleukin-8) levels in bronchoalveolar lavage fluid were measured. Finally, the pulmonary histology of the experimental subjects was examined at the end of experiments. Both of the lavaged groups (dsBAL and dsBAL + Bud) showed significantly better oxygenation than those that had not undergone lavage (control and Bud) (p < 0.05). The dsBAL + Bud group showed a significantly higher lung compliance and required a significantly lower peak inspiratory pressure during the experimental periods than the other three groups (p < 0.05). All treatment groups had significantly lower concentrations of interleukin-1ß concentration in the bronchoalveolar lavage fluid than the control group (p < 0.05). The dsBAL + Bud group also had a significantly lower interleukin-6 concentration in the bronchoalveolar lavage fluid (p< 0.05), as well as a significantly lower lung injury score based on pulmonary histology than the control group (p < 0.05). CONCLUSIONS: Therapeutic bronchoalveolar lavage with diluted surfactant followed by intratracheal instillation of budesonide has a synergistic and beneficial effect when treating severe meconium-injured newborn piglet lungs.

Di-(2-ethylhexyl) phthalate accelerates atherosclerosis in apolipoprotein E-deficient mice.

Di-(2-ethylhexyl) phthalate (DEHP) is associated with atherosclerosis-related cardiovascular disease complications, but we lack direct evidence of its unfavorable effect on atherogenesis. In this study, we aimed to clarify in vivo and in vitro the contribution of DEHP to the development of atherosclerosis and its underlying mechanisms. Apolipoprotein E-deficient (apoE(-/-)) mice chronically treated with DEHP for 4 weeks showed exacerbated hyperlipidemia, systemic inflammation, and atherosclerosis. In addition, DEHP promoted low-density lipoprotein (LDL) oxidation, which led to inflammation in endothelial cells as evidenced by increased protein expression of pro-inflammatory mediators. Furthermore, chronic DEHP treatment increased hepatic cholesterol accumulation by downregulating the protein expression of key regulators in cholesterol clearance including LDL receptor, cholesterol 7α-hydrolase, ATP-binding cassette transporter G5 and G8, and liver X receptor α. Moreover, the adiposity and inflammation of white adipose tissues were promoted in DEHP-treated apoE(-/-) mice. In conclusion, DEHP may disturb cholesterol homeostasis and deregulate the inflammatory response, thus leading to accelerated atherosclerosis.

Regulation of Cigarette Smoke Induction of IL-8 in Macrophages by AMP-activated Protein Kinase Signaling.

Inhaled cigarette smoke (CS) causes persistent lung inflammation in smokers. Interleukin 8 (IL-8) released from macrophages is a key chemokine during initiation and progression of CS-induced lung inflammation, yet its regulation is largely unknown. AMP-activated protein kinase (AMPK), a crucial energy homeostasis regulator, may modulate inflammation. Here we report that CS extract (CSE) increased the level of intracellular reactive oxygen species (ROS), activating AMPK, mitogen-activated protein kinases (MAPKs), and NF-κB, as well as inducing IL-8, in human macrophages. N-acetyl-cysteine (ROS scavenger) or hexamethonium [nicotinic acetylcholine receptor (nAChR) antagonist] attenuated the CSE-induced increase in intracellular ROS, activation of AMPK and NF-κB, as well as IL-8 induction, which suggests that nAChRs and ROS are important. Prevention of AMPK activation by compound C or AMPK siRNA reduced CSE-induced IL-8 production, confirming the role of AMPK. Compound C or AMPK siRNA also inhibited the activation of MAPKs and NF-κB by CSE, which suggests that these molecules are downstream of AMPK. Additionally, exposure of human macrophages to nicotine activated AMPK and induced IL-8 and that these effects were lessened by hexamethonium or compound C, implying that nicotine in CS may be causative. Furthermore, chronic CS exposure in mice promoted AMPK phosphorylation and expression of MIP-2 (an IL-8 homolog) in infiltrated macrophages and in lung tissues, as well as induced lung inflammation, all of which were reduced by compound C treatment. Thus, we identified a novel nAChRs-dependent, ROS-sensitive, AMPK/MAPKs/NF-κB signaling pathway, which seems to be important to CS-induced macrophage IL-8 production and possibly to lung inflammation.

Lung Epithelial TRPA1 Transduces the Extracellular ROS into Transcriptional Regulation of Lung Inflammation Induced by Cigarette Smoke: The Role of Influxed Ca²âº.

The mechanism underlying the inflammatory role of TRPA1 in lung epithelial cells (LECs) remains unclear. Here, we show that cigarette smoke extract (CSE) sequentially induced several events in LECs. The Ca(2+) influx was prevented by decreasing extracellular reactive oxygen species (ROS) with the scavenger N-acetyl-cysteine, removing extracellular Ca(2+) with the chelator EGTA, or treating with the TRPA1 antagonist HC030031. NADPH oxidase activation was abolished by its inhibitor apocynin, EGTA, or HC030031. The increased intracellular ROS was halted by apocynin, N-acetyl-cysteine, or HC030031. The activation of the MAPKs/NF-κB signaling was suppressed by EGTA, N-acetyl-cysteine, or HC030031. IL-8 induction was inhibited by HC030031 or TRPA1 siRNA. Additionally, chronic cigarette smoke (CS) exposure in wild-type mice induced TRPA1 expression in LECs and lung tissues. In CS-exposure trpa1 (-/-) mice, the increased BALF level of ROS was similar to that of CS-exposure wild-type mice; yet lung inflammation was lessened. Thus, in LECs, CSE may initially increase extracellular ROS, which activate TRPA1 leading to an increase in Ca(2+) influx. The increased intracellular Ca(2+) contributes to activation of NADPH oxidase, resulting in increased intracellular ROS, which activate the MAPKs/NF-κB signaling leading to IL-8 induction. This mechanism may possibly be at work in mice chronically exposed to CS.

Influence of serotonergic mechanisms on the urine flow rate in male rats.

This study extensively examined the role of a 5-HT(1A) receptor in controlling voiding function in anesthetized male rats. A simultaneous recording of the intravesical pressure (IVP), external urethral sphincter (EUS)-electromyography (EMG), and urine flow rate (UFR) during continuous cystometry was used. 8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), a 5-HT(1A) receptor agonist, significantly improved the voiding efficiency, as detected by increases in the evoked contraction amplitude, EUS burst period, and silent period, and decreases in the volume threshold, pressure threshold, and residual volume. Interestingly, the UFR during voiding was reduced by 8-OH-DPAT, as evidenced by decreases in the maximal UFR and mean UFRs of the voiding period, spike duration, and interspike interval. Conversely, treating rats with WAY-100635, a 5-HT(1A) antagonist, produced effects opposite to those produced by 8-OH-DPAT. These findings suggest that 8-OH-DPAT improved the voiding efficiency by enhancing the detrusor contractile ability and prolonging EUS burst period, which would compensate for the lower UFR, resulting from urethral smooth muscle contractions and longer EUS silent periods during voiding. The present study contributes to our understanding of the role of 5-HT(1A) receptors in controlling the urine flow rate in male rats.

High expression of high-mobility group box 1 in the blood and lungs is associated with the development of chronic obstructive pulmonary disease in smokers.

BACKGROUND AND OBJECTIVE: High-mobility group box 1 (HMGB1) is an important mediator in multiple pathological conditions, but the expression of HMGB1 in chronic obstructive pulmonary disease (COPD) has not yet been completely investigated. We aimed to analyze the relationship between HMGB1 expression in blood and lung tissue and the development of COPD. METHODS: Twenty-eight patients admitted for single pulmonary surgical intervention were enrolled. The expression of HMGB1 in blood and lung tissue was evaluated by enzyme-linked immunosorbent assay analysis and immunohistochemistry stain, respectively. The study patients were divided into smokers with COPD (n = 11), smokers without COPD (n = 8) and non-smoker healthy controls (n = 9). RESULTS: Smokers with COPD compared with smokers without COPD and healthy controls were older in age, with lower post-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1 /FVC) ratio (63.1 ± 5.5 vs 77.6 ± 3.6 and 84.5 ± 5.8, P < 0.001 and P < 0.001, respectively) and higher levels of plasma HMGB1 (93.2 ± 139.9 vs 7.3 ± 4.8 and 17.0 ± 19.6 ng/mL, P = 0.016 and P = 0.021, respectively). In smokers with COPD, the numbers and portion of HMGB1-expressing cells in epithelium and submucosal areas were significantly increased. Notably, plasma HMGB1 levels negatively correlated with post-bronchodilator FEV1 /FVC ratio (r = -0.585, P = 0.008) in smokers, but not in non-smokers. CONCLUSIONS: In smokers, high expression of HMGB1 in the blood and lungs is related to the lung function impairment and appears to be associated with the development of COPD.

Paeonol attenuates cigarette smoke-induced lung inflammation by inhibiting ROS-sensitive inflammatory signaling.

Cigarette smoking causes persistent lung inflammation that is mainly regulated by redox-sensitive pathways. We have previously reported that cigarette smoke (CS) activates reactive oxygen species- (ROS-) sensitive mitogen-activated protein kinases (MAPKs)/nuclear factor-κB (NF-κB) signaling leading to induction of lung inflammation. Paeonol, the main phenolic compound present in the Chinese herb Paeonia suffruticosa, has antioxidant and anti-inflammatory properties. However, whether paeonol has similar beneficial effects against CS-induced lung inflammation remains unclear. Using a murine model, we showed that chronic CS exposure for 4 weeks caused pulmonary inflammatory infiltration, increased lung vascular permeability, elevated lung levels of chemokines, cytokines, and 4-hydroxynonenal (an oxidative stress biomarker), and induced lung inflammation; all of these CS-induced events were suppressed by chronic treatment with paeonol. Using human bronchial epithelial cells (HBECs), we demonstrated that cigarette smoke extract (CSE) sequentially increased extracellular and intracellular levels of ROS, activated the MAPKs/NF-κB signaling, and induced interleukin-8 (IL-8); all these CSE-induced events were inhibited by paeonol pretreatment. Our findings suggest a novel role for paeonol in alleviating the oxidative stress and lung inflammation induced by chronic CS exposure in vivo and in suppressing CSE-induced IL-8 in vitro via its antioxidant function and an inhibition of the MAPKs/NF-κB signaling.

Promotion of ROS-mediated apoptosis, G2/M arrest, and autophagy by naringenin in non-small cell lung cancer.

Background: As lung cancer is the leading cause of cancer death worldwide, the development of new medicines is a crucial endeavor. Naringenin, a flavanone derivative, possesses anti-cancer and anti-inflammatory properties and has been reported to have cytotoxic effects on various cancer cells. The current study investigated the underlying molecular mechanism by which naringenin induces cell death in lung cancer. Methods: The expression of apoptosis, cell cycle arrest, and autophagy markers in H1299 and A459 lung cancer cells was evaluated using a terminal deoxynucleotidyl transferase dUTP nick end labeling assay (TUNEL), Western blot, Annexin V/PI stain, PI stain, acridine orange staining, and transmission electron microscopy (TEM). Using fluorescence microscopy, DALGreen was used to observe the degradation of p62, a GFP-LC3 plasmid was used to evaluate puncta formation, and a pcDNA3-GFP-LC3-RFP-LC3ΔG plasmid was used to evaluate autophagy flux. Furthermore, the anti-cancer effect of naringenin was evaluated in a subcutaneous H1299 cell xenograft model. Results: Naringenin treatment of lung cancer cells (H1299 and A459) reduced cell viability and induced cell cycle arrest. Pretreatment of cells with ROS scavengers (N-acetylcysteine or catalase) suppressed the naringenin-induced cleavage of apoptotic protein and restored cyclin-dependent kinase activity. Naringenin also triggered autophagy by mediating ROS generation, thereby activating AMP-activated protein kinase (AMPK) signaling. ROS inhibition not only inhibited naringenin-induced autophagic puncta formation but also decreased the ratio of microtubule-associated proteins 1A/1B light chain 3 II (LC3II)/LC3I and activity of the AMPK signaling pathway. Furthermore, naringenin suppressed tumor growth and promoted apoptosis in the xenograft mouse model. Conclusion: This study demonstrated the potent anti-cancer effects of naringenin on lung cancer cells, thereby providing valuable insights for developing small-molecule drugs that can induce cell cycle arrest, apoptosis, and autophagic cell death.

Annexin A1 mediates the anti-adhesive effects of the dexamethasone-treated promyelocytic leukemic cells.

Annexin A1 (AnxA1) is an important anti-inflammatory mediator during granulocytic differentiation in all trans-retinoic acid (ATRA) treated acute promyelocytic leukemic (APL) cells. Dexamethasone has been used successfully to prevent complications in ATRA-treated APL patients, although its mechanism of action is still not clear. In the present study, we have examined the effect of dexamethasone on the modulation of AnxA1 in ATRA-APL NB4 (ATRA-NB4) cells, ATRA-NB4 cells-derived microparticles (MPs) and its role during cell-cell interaction between ATRA-NB4 cells and endothelial cells. Our results have shown that dexamethasone can inhibit the percentage of ATRA-NB4 cells expressing surface AnxA1 and its receptor FPR2/ALX in a time-dependent manner based on flow cytometric analysis. However, dexamethasone treatment of ATRA-NB4 cells has no significant effect on the level of AnxA1 mRNA, the total cellular level of AnxA1 protein or the release of AnxA1 from these cells, as determined by RT-PCR, Western blotting, and ELISA, respectively. Further studies demonstrate that dexamethasone is able to significantly inhibit the adhesion of ATRA-NB4 cells to endothelial cells, and this anti-adhesive effect can be inhibited if the cells were pre-treated with a neutralizing antibody specific for AnxA1. Finally, dexamethasone also enhances the release of AnxA1-containing MPs from ATRA-NB4 cells which can in turn prevent the adhesion of the ATRA-NB4 cells to endothelial cells. We conclude that biologically active AnxA1 originating from dexamethasone-treated ATRA-APL cells and their MPs plays an anti-adhesive effect and this contributes to inhibit the adhesion of ATRA-APL cell to endothelial cells.

Sexually dimorphic urethral activity in response to pharmacological activation of 5-HT1A receptors in the rat.

In this study, we examined the possibility that 5-HT1A receptors may underlie sexually dimorphic mechanisms affecting the regulation of urethral functions in anesthetized rats. Simultaneous recordings of intravesical pressure under isovolumetric conditions, external urethral sphincter-electromyography, and urethral perfusion pressure were used to examine the effects of a 5-HT1A receptor agonist [8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT)] and antagonist (WAY-100635) on bladder and urethral functions. This research also evaluated the effects of 8-OH-DPAT and α-bungarotoxin (a neuromuscular blockade agent) on urethral continence using leak point pressure testing, and the distribution of 5-HT1A receptors in the lower urinary tract was assessed by immunohistochemistry. The serotonergic mechanism that controls the urinary bladder and external urethral sphincter-electromyography activity showed no significant sexual differences, but urethral activity in urethral perfusion pressure and leak point pressure values exhibited some sexual differences. 8-OH-DPAT enhanced urethral pressure during continence in rats of both sexes, but the drug elevated the pressure during voiding in male rats and reduced it in female rats. The distribution of 5-HT1A receptors in the spinal cord also showed some sexual differences. The present study contributes to our understanding of the role of 5-HT1A receptors in physiological and immunohistochemical properties of urethral smooth muscle in rats of different sexes. These findings may be a basis for the future development of pharmacotherapies for stress urinary incontinence in men.

Inflammatory role of AMP-activated protein kinase signaling in an experimental model of toxic smoke inhalation injury.

OBJECTIVE: The molecular mechanisms underlying lung inflammation in toxic smoke inhalation injury are unknown. We investigated the signaling pathway responsible for the induction of interleukin 8 by wood smoke extract in lung epithelial cells and lung inflammation induced by wood smoke exposure in mice. DESIGN: A randomized, controlled study. SETTING: A research laboratory. INTERVENTIONS AND MAIN RESULTS: Exposure of primary human bronchial epithelial cells to wood smoke extract sequentially activated NADPH oxidase and increased intracellular reactive oxygen species level; activated AMP-activated protein kinase, extracellular signal-regulated kinase and Jun N-terminal kinase (two mitogen-activated protein kinases), and nuclear factor-κB and signal transducer and activator of transcription protein 3 (two transcription factors); and induced interleukin-8. Inhibition of NADPH oxidase activation with apocynin or siRNA targeting p47(phox ) (a subunit of NADPH oxidase) attenuated the increased intracellular reactive oxygen species level, AMP-activated protein kinase activation, and interleukin-8 induction. Removal of intracellular reactive oxygen species by N-acetyl-cysteine reduced the activation of AMP-activated protein kinase, extracellular signal-regulated kinase and Jun N-terminal kinase, and interleukin-8 induction. Prevention of AMP-activated protein kinase activation by Compound C or AMP-activated protein kinase siRNA lessened the activation of Jun N-terminal kinase, extracellular signal-regulated kinase, nuclear factor-κB, signal transducer and activator of transcription protein 3 and interleukin-8 induction. Inhibition of Jun N-terminal kinase and extracellular signal-regulated kinase activation by inhibitors reduced the activation of nuclear factor-κB and signal transducer and activator of transcription protein 3 and interleukin-8 induction. Abrogation of nuclear factor-κB and signal transducer and activator of transcription protein 3 activation by inhibitors attenuated the interleukin-8 induction. Additionally, acute exposure of mice to wood smoke promoted AMP-activated protein kinase phosphorylation and expression of macrophage inflammatory protein 2 (an interleukin-8 homolog) in lung epithelial cells and lungs and lung inflammation, all of which were reduced by Compound C treatment. CONCLUSIONS: Interleukin-8 induction by wood smoke extract in lung epithelial cells is mediated by novel NADPH oxidase-dependent, reactive oxygen species-sensitive AMP-activated protein kinase signaling with Jun N-terminal kinase and extracellular signal-regulated kinase as the downstream kinases and nuclear factor-κB and signal transducer and activator of transcription protein 3 as the downstream transcription factors. This AMP-activated protein kinase signaling is likely important for inducing lung inflammation with toxic smoke exposure in mice.

Development of monocyte Toll-like receptor 2 and Toll-like receptor 4 in preterm newborns during the first few months of life.

BACKGROUND: Although the immaturity of Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) at birth in preterm newborns is known, their development during the first few months of life remains unclear. METHODS: Blood monocytes of preterm newborns (gestational age: 24-36 wk) were obtained every 2 wk when possible in order to perform serial measurements of TLR2 and TLR4 surface expression, as well as lipopolysaccharide (LPS)-induced cytokine production. Measurements using monocytes from term newborns and adults were also performed. RESULTS: The monocytes of preterm newborns obtained at birth displayed reduced surface expression of TLR2 and TLR4, and diminished responses of tumor necrosis factor-α (TNF-α) and interleukin (IL)-8 to LPS stimulation. Regardless of gestational age, monocyte expression of TLR2 and TLR4 in preterm newborns increased rapidly within the first 2 wk after birth, quickly reaching those of term newborns. These increases continued for the following 4-6 wk, although the increase began to plateau. By contrast, LPS-induced production of TNF-α and IL-8 did not elevate over this period in preterm newborns. CONCLUSION: The blood monocytes of preterm newborns display rapid increase in TLR2 and TLR4 expression during the first few months of life, whereas LPS-induced cytokine production functionality did not improve in parallel.

Cell cycle regulation by glucosamine in human pulmonary epithelial cells.

Airway epithelial cells play an important role against intruding pathogens. Glucosamine, a commonly used supplemental compound, has recently begun to be regarded as a potential anti-inflammatory molecule. This study aimed to uncover how glucosamine impacts on cellular proliferation in human alveolar epithelial cells (A549) and bronchial epithelial cells (HBECs). With trypan blue-exclusion assay, we observed that glucosamine (10, 20, 50 mM) caused a decrease in cell number at 24 and 48 h; with a flow cytometric analysis, we also noted an enhanced cell accumulation within the G(0)/G(1) phase at 24 h and induction of late apoptosis at 24 and 48 h by glucosamine (10, 20, 50 mM) in A549 cells and HBECs. Examination of phosphorylation in retinoblastoma (Rb) protein, we found an inhibitory effect by glucosamine at 20 and 50 mM. Glucosamine at 50 mM was demonstrated to elevate both the mRNA and protein expression of p53 and heme oxygenase-1 (HO-1), but also caused a reduction in p21 protein expression. In addition, glucosamine attenuated p21 protein stability via the proteasomal proteolytic pathway, as well as inducing p21 nuclear accumulation. Altogether, our results suggest that a high dose of glucosamine may inhibit cell proliferation through apoptosis and disturb cell cycle progression with a halt at G(0)/G(1) phase, and that this occurs, at least in part, by a reduction in Rb phosphorylation together with modulation of p21, p53 and HO-1 expression, and nuclear p21 accumulation.

Role of TRPA1 and TRPV1 in the ROS-dependent sensory irritation of superior laryngeal capsaicin-sensitive afferents by cigarette smoke in anesthetized rats.

BACKGROUND: Laryngeal exposure to cigarette smoke (CS) evokes sensory irritation, but the mechanisms are largely unclear. The TRPA1 and TRPV1 receptors are two types of Ca(2+)-permeant channels located at the terminals of airway capsaicin-sensitive afferents. We investigated the mechanisms underlying the airway reflex evoked by laryngeal CS exposure in anesthetized rats. METHODS: CS (7 ml) was delivered into a functionally isolated larynx, while the animals (n = 201) breathed spontaneously. Respiratory parameters were measured. All use of pharmacological agents involved pretreatment by laryngeal application. RESULTS: Laryngeal CS exposure immediately evoked a concentration-dependant apneic response that was unrelated to the nicotine content of the CS. This inhibition of breathing was abolished by bilateral sectioning of the superior laryngeal nerves (SLNs) or by perineural capsaicin treatment of the SLNs (selective blocking of capsaicin-sensitive afferent neural conduction), suggesting the involvement of superior laryngeal capsaicin-sensitive afferents in the reflex. The reflex apnea was significantly attenuated by N-acetyl-l-cysteine (antioxidant), EGTA (extracellular Ca(2+) chelator) and BAPTA-AM (intracellular Ca(2+) chelator), indicating the importance of reactive oxygen species (ROS) and Ca(2+). This reflex apnea was also partially reduced by HC030031 (TRPA1 receptor antagonist) and capsazepine (TRPV1 receptor antagonist), and was nearly abolished by a combination of these two antagonists, suggesting a central role for the TRPA1 and TRPV1 receptors. Furthermore, the reflex apnea was attenuated by indomethacin (cyclooxygenase inhibitor); however, the attenuation by indomethacin was not increased by pretreatment with HC030031 or capsazepine, indicating that TRPA1 and TRPV1 receptor functionality is, at least in part, linked to cyclooxygenase metabolites. CONCLUSIONS: The reflex apnea evoked by laryngeal CS requires activation of both TRPA1 and TRPV1 receptors, which are likely to be located at the terminals of superior laryngeal capsaicin-sensitive afferents. Laryngeal sensory irritation by CS seems to depend on the actions of ROS and cyclooxygenase metabolites on these two types of receptors.