Variable p-CREB expression depicts different asthma phenotypes

BACKGROUND

Chromatin modification may play a role in inflammatory gene regulation in asthma. Cyclic adenosine mono-phosphate response element-binding protein (CREB), with the specific co-activator, the CREB-binding protein (CBP), contributes to the acetylation of chromatin and to the transcription of pro-inflammatory genes.

OBJECTIVES

To evaluate the expression of CBP and of phospho-CREB (p-CREB) in bronchial biopsies and in peripheral blood mononuclear cells (PBMC) of controls (C), untreated (UA), inhaled steroid treated (ICS) and steroid-dependent asthmatic (SDA) patients.

METHODS

We used immunohistochemistry in bronchial biopsies and western blot analysis and immunocytochemistry in PBMC.

RESULTS

Cyclic adenosine mono-phosphate response element-binding protein expression, in the epithelium was similar in all groups, while p-CREB expression was increased in UA and in SDA in comparison with ICS and C subjects (C vs UA P = 0.002, C vs SDA P = 0.007), (ICS vs SDA P = 0.005), (ICS vs UA P = 0.001). Interestingly, also in the submucosa, p-CREB was increased in UA and SDA in comparison with ICS and C subjects (C vs UA P = 0.0004) (C vs SDA P < 0.0001) (ICS vs UA P = 0.002) (ICS vs SDA P < 0.0001) and positively correlated with leukocyte infiltration within the bronchi (CD45RB+ cells). Similar results were obtained with PBMC isolated from the same patient groups. Incubation of PBMC in vitro, with fluticasone propionate, decreased the p-CREB expression induced by cytokine activation (interferon-gamma, tumor necrosis factor-alpha).

CONCLUSIONS

This study demonstrates that the expression of p-CREB is related, in asthma, to the persistent inflammation according to the disease severity. p-CREB expression can be modulated by glucocorticoids in responsive patients.

Hypoallergenic fragment of Par j 2 increases functional expression of Toll-like receptors in atopic children

BACKGROUND

Parietaria judaica (Par j) is one of the main causes of allergy in the Mediterranean countries. The activation of Toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) inhibits nasal inflammation of atopic children.

OBJECTIVE

To examine, in vivo and in vitro, the effect of recombinant Par j 2 (rPar j 2) and of its fragments (1-55 and 52-102) on atopic children.

METHODS

We used skin prick test for in vivo evaluations. We assessed, in vitro, in peripheral blood mononuclear cells (PBMC), the effect of rPar j 2 and of the two fragments on neutrophil chemotaxis, on CD45RO, on TLR2 and TLR4 expression, on LPS binding and on interferon (IFN)-gamma release, by a microchemotaxis chamber, by flow cytometry and by enzyme-linked immunosorbent assay, respectively.

RESULTS

In vivo while rPar j 2 induced a positive skin reaction, 1-55 and 52-102 fragments did not. In vitro, while rPar j 2 increased both CD45RO expression and neutrophils chemotaxis in PBMC, both Par j 2 fragments did not. 1-55 fragment of Par j 2 upregulated both TLR2 and TLR4 expression and LPS binding, while the rPar j 2 and 52-102 fragment did not. Finally, 1-55 fragment of Par j 2 induced IFNgamma release, while the rPar j 2 and 52-102 fragment did not.

CONCLUSIONS

Hypoallergenic 1-55 fragment, upregulating innate immunity receptors and increasing IFNgamma, might re-orientate, in atopics, the immune system toward a physiologic balance between Th1 and Th2 responses.

What is a clinically significant improvement in the intensity of fatigue among cancer patients?

8560

Background: Fatigue is the most common symptom in cancer patients. The FACIT-F fatigue subscale and the ESAS Fatigue 0–10 are the most commonly used scales for research and clinical care, respectively. However, clinically significant improvement has not been well established. Methods: We reviewed the data from 3 RCTs of fatigue in 194 patients. In all cases patients completed the FACIT-F and ESAS at baseline and Day 8. All patients also provided a global benefit score [1=not beneficial, 7=greatly important] during Day 8 reflecting their global perception of fatigue improvement. All patients who reported their global perception as ≥ 4 [moderate improvement, consistent benefit] were considered to have a clinically significant improvement. We determined the median [25–75% quartiles] change in ESAS and FACIT-F as well as their screening performance when using the clinically significant difference to define responder status. Results: Mean age was 56 ± 12 years. 72 patients [37%] were female. Median baseline FACIT-F and ESAS scores were 18 ± 8 and 7.5 ± 1.7, respectively. Patients who reported a clinically significant improvement had a median [quartiles] change of 4 [3–6 ] in ESAS and 17 [9–25 ] in FACIT-F sub score resulting in a specificity of 72% for ESAS and 93% for FACIT-F, respectively. The sensitivity, positive predictive value and negative predictive value for ESAS were 66%, 56%, and 78%, and for FACIT-F were 52%, 81%, 76%, respectively. The correlation between global benefit score and change in ESAS was 0.57 [p<0.001], global benefit score and change in FACIT-F was 0.61 [p=0.001], and change in FACIT-F and change in ESAS was 0.62 [p≤0.001]. Conclusions: A difference in ≥ 4 in the ESAS and ≥ to 17 in the FACIT-F can be considered clinically significant in patients with cancer fatigue. The FACIT-F score showed higher specificity. Improvements in the FACIT-F score reported in clinical trials of fatigue are frequently not clinically significant. More research is needed to better characterize responder status in cancer fatigue.

No significant financial relationships to disclose.

The use of palliative sedation for intractable symptoms in a palliative care unit (PCU) in a comprehensive cancer center

8577

Background: There is wide variation in the frequency of reported use of palliative sedation (PS) to control intractable and refractory symptoms. Institutions have established policies for midazolam infusion in cases of PS. The indications and outcomes of this procedure have not been well characterized Methods: Our midazolam policy for PS requires 1:1 nursing for the first 24 hours and documentation of discussions regarding sedation. We reviewed our PCU database for all admissions for the first 11 months of 2005. We used pharmacy records for all patients who received medications used for sedation (chlorpromazine, lorazepam, midazolam). We reviewed all charts of pts who received any of these drugs to establish if the indication had been PS. Results: 148/484 admissions died in the PCU [31%]. 65/484 admissions (13%), and 47/ 148 patients who died (32%) received PS. Median age of patients (pts) was 58, 42 pts were male [65%], and the most frequent primaries observed were lung 24 [37%], hematologic 12 [18%], head and neck 7 [11%], and gastrointestinal 7 [11%]. Results are indicated in the table. * 2 patients had more than one indication for sedation The main causes for PS in our patients were delirium 57 [88%], dyspnea 6 [9%], and bleeding 4 [6%]. 18/65 patients who received PS [35%] were discharged alive, versus 318/419 [76%] who did not receive PS [p< 0.001]. Midazolam was used in 11/65 episodes [17%]. 4/6 pts with PS for dyspnea received midazolam [66%], versus 8/57 with PS for delirium or bleeding [14%], p=0.01]. 18/54 pts who received PS using other drug were discharged alive [33%], versus 0/11 pts who received midazolam [p=0.02]. Conclusions: Palliative sedation was required in 32% of pts who died in the hospital. Reporting midazolam utilization rates for monitoring overall PS outcomes, results in significant under reporting. Midazolam was used more frequently in cases of progressive dyspnea and poor prognosis. Less restrictive policies in the use of midazolam may result in more use for PS. Data accrual continues.

[Table: see text]

No significant financial relationships to disclose.

The impact of physician’s sequence [1st vs 2nd] and posture [sitting vs standing] on cancer patients’ physician preference and perception of compassion

18513

Background: Our group previously found in a cross-over RCT in 69 advanced cancer patients [P] that the sitting posture was preferred; we also found that patients consistently chose the physician [MD] they observed in 2nd order [ASCO 2003:2958]. The effect of sequence on MD preference and perception of compassion had not been reported before. The purpose of this study was to assess if P preferred MD seen in 2nd order after controlling for posture. Methods: Advanced cancer P were randomized to observe 2 9-minute videos of a P/MD interaction. Both videos were identical except for the posture of the MD [sitting versus standing]. After a 2–3 minute assessment P were crossed-over into viewing the opposite video. Investigators were blinded to the type of video observed. P were blinded to the purpose of the study and difference between videos. Results: 168 P [98%] were evaluable. The mean perception of compassion [0 = worst, 50 = best] was 29 ± 13 for the 1st MD versus 33 ± 11 for the 2nd MD [p < 0.001]. P also preferred sitting [33 ± 11] versus standing [29 ± 12, p < 0.001]. The overall impression [0 = worst, 10 = best] for the MD seen 2nd versus 1st was 6.5 ± 2.3 versus 5.7 ± 2.7 [p ≤ 0.001]. All differences in response were independent on posture. 119/168 P [71%] perceived a difference between the 2 MDs and this difference was considered ≥ moderately important in 95 P [80%]. 76/168 P preferred the 2nd MD [45%, 95% CI, 38–53], 38/168 P preferred the 1st MD [23%, 95% CI, 16–29], and 54/168 P had no preference [32%, 95% CI, 25–39]. 49/114 P who expressed a preference perceived their preferred MD had spent more time with the P [43%]. 87/168 P preferred their MD to sit [52%] but they considered posture more important than time in 23 cases [20%], friendliness in 18 [15%], patience in 16 [14%], caring in 15 [14%], and respect in 18 [16%]. Conclusions: P prefer MDs they see in 2nd order, they have an overall better impression of them and consider them more compassionate, and they perceive that they spent more time with their P, independently on the MD’s chosen posture. Most P also prefer MDs to sit but posture is rated as a relatively low priority in P/MD communication. These findings are important for clinical care and trial participation.

No significant financial relationships to disclose.

Evidence for a kaon-bound state K(-)pp produced in K(-) absorption reactions at rest

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively.

LTB4 is present in exudative pleural effusions and contributes actively to neutrophil recruitment in the inflamed pleural space

The pleural space is a virtual compartment between the lung and chest wall that becomes filled with fluid and inflammatory cells during a variety of respiratory diseases. Here, we study the potential role of the eicosanoid metabolite leukotriene B4 (LTB4) in disparate diseases leading to acute (pneumonia) or chronic (tuberculosis, cancer) inflammation of the pleural space. LTB4 concentrations were significantly higher in pleural fluid due to pneumonia, tuberculosis and cancer with respect to congestive heart failure and correlated with neutrophil elastase, which is used as an indication of state of activation of neutrophils in the pleural space. Moreover, pleural LTB4 was biologically active, as an anti-LTB4 antibody partially neutralized the chemotactic activity of parapneumonic, tuberculous and cancer effusions. Macrophages, neutrophils, lymphocytes, mesothelial cells and cancer cells all expressed mRNA for 5-lipoxygenase, the enzyme that initiates leukotriene synthesis leading to the production of LTB4, in exudative pleural effusions. Upon stimulation in transudative pleural effusions, pleural macrophages produced, in a time-dependent fashion, a significantly higher concentration of LTB4 than mesothelial cells. These studies demonstrate that different cell types are capable of producing LTB4 in the inflamed pleural space and that this mediator may play a crucial role in the recruitment of neutrophils into the pleural space.

Fluticasone induces apoptosis in peripheral T-lymphocytes: a comparison between asthmatic and normal subjects

Apoptosis is an important mechanism allowing inflammation to be limited. Glucocorticoids are the most effective anti-inflammatory agents in asthma therapy and induce cell apoptosis. Since T-lymphocytes are critically involved in airway inflammation in asthma, the effects of fluticasone propionate (FP) on apoptosis in unstimulated and in interleukin (IL)-2 stimulated peripheral blood T-lymphocytes (PBTs) isolated from 14 normal and 19 mild-to-moderate asthmatic subjects were evaluated. Apoptosis was evaluated by: deoxyribonucleic acid (DNA) fragmentation electrophoresis, DNA content, annexin V binding, apoptosis related markers (Fas, B-cell lymphona leukaemia-2 (Bcl-2), Bax, and CD25), and by electron microscopy. FP induced apoptosis in unstimulated PBTs of normal and asthmatic subjects in a time-dependent fashion. In asthma, this effect was associated with a significant decrease of Bcl-2 expression, and with an increase of Bax/Bcl-2 ratio. In PBTs of asthmatics, FP also reduced Fas and CD25 expression. Moreover, in IL-2-stimulated PBTs from both asthmatics and normal subjects, FP was able to induce apoptosis and to reduce Bcl-2, Fas and CD25 expression, whereas negligible effects were detected on Bax expression. This study shows that the glucocorticosteroid, fluticasone, increases apoptosis and modulates expression of apoptosis-related markers in unstimulated and in interleukin-2 stimulated T-lymphocytes. This points towards a potential mechanism by which fluticasone exerts its anti-inflammatory effects.

A bio-dosemeter that utilises isolated enzymes to detect ionising radiation

The development of a biosensor for the detection of ionising radiation (biodosemeter) utilising the advantageous properties of the photosystem II (PSII) complex and its response to ionising radiation is reported. The transducer signal for this biosensor can be fluorescence, which is dependent on photosynthetic activity. Exposure of biological material to ionising radiation leads to a loss of function due to the destruction of critical structures. Radiation target theory predicts an exponential decrease in biochemical activity that is dependent on the absorbed radiation energy and directly proportional to the mass of the individual molecules possessing this activity. The activity is lost whenever the protein is hit since very high energy is transferred through the chain. Several approaches were used to optimise the immobilisation of PSII complexes to improve the sensitivity of the bio-dosemeter.

HLA-DRB1*1501 and response to copolymer-1 therapy in relapsing-remitting multiple sclerosis

BACKGROUND

Copolymer 1 (Cop-1) is a random synthetic amino acid copolymer, effective in the treatment of the relapsing-remitting form of MS (RRMS). In vitro and in vivo studies suggest that the mechanism of Cop-1 involves its binding to major histocompatibility complex class II molecules as an initial step.

OBJECTIVE

To assess a possible relationship between human leukocyte antigen (HLA) alleles and response to Cop-1 therapy.

METHODS

Eighty-three patients with RRMS, 44 treated with Cop-1 and 39 with interferon beta-1a (IFNbeta-1a) for 2 years, were typed by molecular methods for HLA class II genes and subgrouped according to clinical outcome.

RESULTS

Data have shown a possible positive correlation between presence of DRB1*1501 and response to Cop-1 therapy (p = 0.008). No relationship between HLA alleles and therapy has been found in IFNbeta-1a treated patients.

CONCLUSIONS

Results suggest that DRB1*1501 might be relevant for the clinical outcome in Cop-1 treated patients and, if confirmed in larger studies, it could be helpful in the selection of RRMS patients for different therapeutic options.

Precision measurement of the spin-dependent asymmetry in the threshold region of 3He(e, e')

We present the first precision measurement of the spin-dependent asymmetry in the threshold region of 3He(e,e') at Q2 values of 0.1 and 0.2 (GeV/c)2. The agreement between the data and nonrelativistic Faddeev calculations which include both final-state interactions and meson-exchange current effects is very good at Q2 = 0.1 (GeV/c)2, while a small discrepancy at Q2 = 0.2 (GeV/c)2 is observed.

Crohn disease: susceptibility and disease heterogeneity revealed by HLA genotyping

Predisposition to Crohn disease (CD) seems to be genetically determined but, though several reports on the matter, the association between HLA antigens and the disease is still controversial. PCR-SSP high resolution typing in 107 CD patients, and in subgroups selected according to clinical features, showed a positive association with the rare haplotype DRB1*07, DQB1*0303 both in the overall patients (p = 0.002; pc = ns) and in the subgroup of nonfistulized patients (p = 0.0008; pc = 0.032). Moreover, the protective role of the haplotype DRB1*03, DQB1*0201 (p = 0.029) was confirmed also in Italian patients, whereas no strong association with HLA class I alleles has been found. In addition, variability of the HLA alleles frequency in CD subgroups was observed, supporting the hypothesis of a genetic heterogeneity of the disease and suggesting that HLA alleles distribution in selected groups may allow to identify patients with probably different prognosis or associated complications.

L-arginine supplementation in young renal allograft recipients with chronic transplant dysfunction

AIMS

L-arginine (LA), the precursor of nitric oxide (NO), was suggested to be beneficial in many forms of renal disease: hypertension, ureteral obstructive nephropathy and cyclosporin A (CsA) nephrotoxicity.

METHODS

Thus, we investigated the effects of LA supplementation on renal function, proteinuria and blood pressure (BP) in young renal allograft recipients with chronic renal transplant dysfunction treated with CsA. Eleven CsA-treated renal allograft recipients with chronic transplant dysfunction, aged 11-22 years, were randomly assigned to a 6-week treatment period with placebo (P), followed by 2 subsequent 6-week periods with LA supplementation (0.1 g/kg body weight/day) or a 6-week treatment period with LA, followed by 2 subsequent 6-week periods with P. At the end of each treatment period 24-hour BP recordings were made, and GFR (Inutest), RPF (PAH clearance) and the urinary excretion of protein, albumin, nitrate, cGMP and urea were evaluated.

RESULTS

In comparison to placebo, LA treatment did not significantly change GFR, RPF, proteinuria and albuminuria, mean systolic or diastolic BP. The urinary excretion of urea and NO3 increased after LA supplementation (uUrea: LA 26.3 +/- 4.6 compared to P 23.5 +/- 4.7 g/day/1.73 m3, p < 0.05, uNO3: LA 514 +/- 152 compared to P 95 +/- 41 mM/day/1.73 m3, p < 0.05), whereas urinary excretion of cGMP remained unchanged.

CONCLUSION

LA supplementation did not improve renal function and did not decrease proteinuria in CsA-treated renal allograft recipients with chronic transplant dysfunction possibly because of inhibition of NO-cGMP forming mechanism.

Effects of gemcitabine on cell proliferation and apoptosis in non-small-cell lung cancer (NSCLC) cell lines

We evaluated the antiproliferative and the proapoptotic ability of gemcitabine in three non-small-cell lung cancer (NSCLC) cell lines. NCI-H292 (mucoepidermoid carcinoma), NCI-CorL23 (large-cell carcinoma) and NCI-Colo699 (adenocarcinoma) cells were cultured with and without 0.5, 0.05 and 0.005 microM gemcitabine for 24, 48 and 72 h, respectively. Gemcitabine exerted a stronger and earlier antiproliferative and proapoptotic effect on H292 cells than on CorL23 or Colo699 cells. Fas receptor expression was increased in all three cell lines and was higher in Colo699 than in CorL23 cells. The incubation of NSCLC with anti-Fas agonistic monoclonal antibody (CH11) induced cell apoptosis in H292 cells, demonstrating that the Fas receptor was functionally active. Finally, gemcitabine and CH-11 exerted a synergistic effect on cell apoptosis in H292 cells. This study demonstrates that gemcitabine induces apoptosis in NSCLC and that this effect might be exerted by modulating functionally active Fas expression, and these effects of gemcitabine were stronger in H292 cells than in either CorL23 or Colo699 cells.

Transverse asymmetry AT' from the quasielastic 3He(e,e') process and the neutron magnetic form factor

We have measured the transverse asymmetry A(T') in 3He(e,e(')) quasielastic scattering in Hall A at Jefferson Laboratory with high precision for Q2 values from 0.1 to 0.6 (GeV/c)(2). The neutron magnetic form factor G(n)(M) was extracted based on Faddeev calculations for Q2 = 0.1 and 0.2 (GeV/c)(2) with an experimental uncertainty of less than 2%.

15(S)-HETE modulates LTB(4) production and neutrophil chemotaxis in chronic bronchitis

We evaluated the levels of 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE] and the expression of 15-lipoxygenase (15-LO) mRNA in induced sputum obtained from 10 control and 15 chronic bronchitis subjects. 15(S)-HETE was evaluated by reverse phase high-performance liquid chromatography separation followed by specific RIA. 15-LO mRNA expression was determined by primed in situ labeling. The levels of both soluble and cell-associated 15(S)-HETE resulted significantly higher in chronic bronchitis than in control subjects. The percentage of cells expressing 15-LO mRNA was significantly higher in chronic bronchitis than in control subjects (P < 0.01). Double staining for specific cell type markers and 15-LO mRNA showed macrophages and neutrophils positive for 15-LO, whereas similar staining of peripheral blood neutrophils did not show evidence for 15-LO expression, suggesting that expression of 15-LO in neutrophils takes place on migration into the airways. Because 15(S)-HETE inversely correlated with the percentage of neutrophils in sputum of chronic bronchitis subjects, we studied the effect of 15(S)-HETE on leukotriene B(4) (LTB(4)) production in vitro and evaluated the concentration of LTB(4) in induced sputum and the contribution of LTB(4) to the chemotactic activity of induced sputum samples ex vivo. The results obtained indicate that macrophages and neutrophils present within the airways of chronic bronchitis subjects express 15-LO mRNA; increased basal levels of 15(S)-HETE may contribute to modulate, through the inhibition of 5-lipoxygenase metabolites production, neutrophil infiltration and airway inflammation associated with chronic bronchitis.

15-Lipoxygenase expression and 15(S)-hydroxyeicoisatetraenoic acid release and reincorporation in induced sputum of asthmatic subjects

BACKGROUND

Recent evidence shows that 15(S)-hydroxy-eicoisatetraenoic acid (15[S]-HETE) can be released and rapidly reincorporated into cellular lipids. These mechanisms exert several immunoregulatory functions that may be relevant in airway inflammation.

OBJECTIVE

Our purpose was to evaluate the levels of both soluble and cell-associated 15(S)-HETE and to examine 15-lipoxygenase (15-LO) messenger RNA (mRNA) expression in sputum samples obtained from 10 control and 18 asthmatic subjects.

METHODS

Levels of 15(S)-HETE were measured by reverse-phase HPLC separation followed by RIA in supernatants and in cell membrane-extracted phospholipids after acid hydrolysis. 15-LO mRNA was evaluated by primed in situ hybridization (PRINS). Combined immunocytochemistry and PRINS was used to identify the phenotype of cells bearing 15-LO transcripts.

RESULTS

Levels of both soluble and cell-associated 15(S)-HETE were higher in asthmatic than in control subjects (P <.0001). The percentage of cells expressing 15-LO mRNA was higher in asthmatic than in control subjects (P <.01). On double staining for specific cell-type markers and 15-LO mRNA, macrophages were the major source for 15-LO.

CONCLUSION

This study shows that the induced sputum technique allows the evaluation of 15-LO activity and that soluble, cell-associated 15(S)-HETE and 15-LO levels are higher in asthmatic than in control subjects. In addition, this study indicates that, in induced sputum, airway macrophages are the major source of 15(S)-HETE in asthma.

Interleukin-8 induces lymphocyte chemotaxis into the pleural space. Role of pleural macrophages

The pleural space is a potential compartment between the lung and chest wall that becomes filled with fluid and inflammatory cells in a number of respiratory diseases. In an attempt to understand one aspect of the inflammatory process in the pleural space, we compared the responses in three different diseases (congestive heart failure [CHF], tuberculosis [TB], and cancer). Large concentrations of interleukin-8 (IL-8) were detected in cancer and TB effusions, but not in CHF. Surprisingly, the concentration of IL-8 correlated best with lymphocyte recruitment and not with neutrophil recruitment. Pleural fluid from cancer and TB patients was chemotactic for lymphocytes, and this activity was partly blocked by an anti-IL-8 antibody in cancer and completely blocked in TB. To determine whether there was the potential for a chemotactic gradient into the pleural space, pleural effusion cells were analyzed for the expression of IL-8. Cells in the effusions of cancer patients expressed IL-8, whereas IL-8 could not be detected from the cells of TB and CHF effusions. To explore the possible role of pleural macrophages in the regulation of IL-8, pleural effusion cells were treated with culture supernatants from stimulated pleural macrophages. Stimulated pleural macrophages were able to induce expression of messenger RNA (mRNA) for IL-8 and IL-8 protein production, and this activity was abrogated by blocking tumor necrosis factor-alpha. These findings suggest that soluble IL-8 is an important factor for the recruitment of lymphocytes into the pleural space, and that this cytokine is produced by both pleural structural and cancer cells after their activation by macrophage-derived, cytokine-mediated signals.

Interleukin-4 enhances 15-lipoxygenase activity and incorporation of 15(S)-HETE into cellular phospholipids in cultured pulmonary epithelial cells

15(S)-Hydroxyeicosatetraenoic acid (15[S]-HETE) is a 15-lipoxygenase (15-LO) metabolite that may play an important role in different pulmonary diseases. 15-HETE is synthesized by different epithelial cells and may be subsequently incorporated into cellular phospholipids. We studied the role of interleukin-4 (IL-4) on 15-LO activity and on 15(S)-HETE incorporation into cellular phospholipids by WI-26 pulmonary epithelial cells. 15-LO activity was evaluated by measuring 15(S)-HETE production, through combined reverse-phase-high-pressure liquid chromatography (RP-HPLC) separation and specific radioimmunoassay (RIA), after incubation with arachidonic acid (AA). We also studied 15-LO messenger RNA (mRNA) expression, using primed in situ (PRINS) labeling. IL-4 (10 ng/ml) markedly increased the percentage of 15-LO mRNA-bearing cells as well as 15-LO activity after 24, 48, and 72 h, with a maximal response at 48 h. Uptake and incorporation into cellular phospholipid was studied with [3H]15(S)-HETE, which showed that IL-4 was able to increase significantly 15(S)-HETE incorporation into WI-26 cells, with a maximal effect observed at 72 h. Cellular-lipid-associated [3H]15(S)-HETE, evaluated with RP-HPLC after base-catalyzed hydrolysis, increased concomitantly with disappearance of the radiolabel from the supernatant. Class separation of cellular lipids with normal-phase HPLC (NP-HPLC) showed that IL-4 increased [3H]15(S)- HETE incorporation mainly in the phosphatidylinositol (PI) fraction. The ability of IL-4 to promote 15-LO activity and incorporation into cellular phospholipids of human lung epithelial cells may be important in airway inflammation and in modulation of the potential autocrine function of 15(S)-HETE.

Phenotypic and functional characterization of normal rat pleural macrophages in comparison with autologous peritoneal and alveolar macrophages

Pleural mononuclear phagocytes (PleMP) were isolated from normal rats by pleural lavage and compared with autologous peritoneal (PerMP) and bronchoalveolar mononuclear phagocytes (BAMP) isolated by peritoneal and bronchoalveolar lavage, respectively. The phagocytic activity of PleMP, PerMP, and BAMP, evaluated by testing their ability to ingest latex beads, was lower for PleMP and PerMP than for BAMP. The phenotype of PleMP, PerMP, and BAMP was characterized by immunocytochemical staining with a panel of monoclonal antibodies (mAbs). As expected, PleMP, PerMP, and BAMP did not react with OX19, OX33, ED5, MOM/3F12/F2, and anticytokeratin mAbs, specific for T lymphocytes, B lymphocytes, dendritic cells, granulocytes, and epithelial/mesothelial cells, respectively. Moreover, PleMP and PerMP populations were highly enriched with OX6-, OX42-, ED7-, and ED8-positive MP, whereas BAMP population was enriched with ED1- and ED9-positive cells. To test the ability of PleMP, PerMP, and BAMP to function as accessory cells (AC), mitomycin C-treated MP were used as stimulatory cells in mixed leukocyte reaction experiments, using allogeneic T cells as responders. 3HdTR incorporation by T cells was assessed as an index of AC function. PleMP and PerMP were more potent AC than BAMP. Moreover, when cultured together with autologous pulmonary interstitial dendritic cells, PleMP and PerMP exerted a more potent ability to stimulate T-cell proliferation than did BAMP. To investigate the capacity of MP to function as bactericidal and fungicidal cells, we tested their ability to kill Escherichia coli and Cryptococcus neoformans, respectively. PleMP and PerMP were less potent bactericidal and fungicidal cells than BAMP. The results of this study demonstrate that PleMP isolated from normal rat pleural space are functionally and phenotypically different from BAMP but similar to PerMP, and suggest that these cells might play an important role in cell-mediated immune reactions in the pleural space.