Use of mucolytics in COPD: A Delphi consensus study

BACKGROUND

International guidelines recommend mucolytic agents as add-on therapy in selected patients with COPD because they may reduce exacerbations and improve health status. As the evidence varies among mucolytic agents, we used the Delphi method to assess consensus amongst an international panel of COPD experts on mucolytics use in COPD.

METHODS

53 COPD experts from 12 countries were asked to complete an online questionnaire and rate their agreement with 15 statements using a 5-point scale. The mucolytic agents evaluated were carbocysteine, erdosteine and N-acetylcysteine (NAC). Data were collected anonymously and consensus presented using descriptive statistics.

RESULTS

The 47 respondents reached consensus on the statements. They agreed that regular treatment with mucolytic agents effectively reduces the frequency of exacerbations, reduces the duration of mild-to-moderate exacerbations, and can increase the time to first exacerbation and symptom-free time in COPD patients. Consensus was consistently highest for erdosteine. The experts agreed that all three mucolytics display antioxidant and anti-inflammatory activity. Erdosteine and NAC were thought to improve the efficacy of some classes of antibacterial drugs. All three mucolytics were considered effective for the short-term treatment of symptoms of acute exacerbations when added to other drugs. The panel agreed that approved doses of mucolytic agents have favorable side-effect profiles and can be recommended for regular use in patients with a bronchitic phenotype.

CONCLUSIONS

Consensus findings support the wider use of mucolytic agents as add-on therapy for COPD. However, the differences in pharmacological actions and clinical effectiveness must be considered when deciding which mucolytic to use.

Lefamulin vs moxifloxacin for community-acquired bacterial pneumonia

Lefamulin is a novel pleuromutilin antibiotic with potent in vitro activity against key community-acquired bacterial pneumonia (CABP) pathogens. However, the clinical efficacy and safety of lefamulin for treating CABP remains unclear.An integrated analysis of 2 phase III trials investigating the clinical efficacy and safety of lefamulin vs moxifloxacin in the treatment of CABP was conducted.A total of 1289 patients (lefamulin group: 646 and moxifloxacin group: 643) were included in this analysis. The early clinical response rate was 89.3% and 90.5% among lefamulin and moxifloxacin group, respectively. Lefamulin was noninferior to moxifloxacin (89.3% vs 90.5%, RR: 0.99, 95% CI: 0.95-1.02, I = 0%). In terms of clinical response at test of cure, no significant difference was observed between the lefamulin and moxifloxacin groups (for modified intention to treat population, RR: 0.98, 95% CI: 0.94-1.02, I = 0%; for clinically evaluable population, RR: 0.96, 95% CI: 0.93-1.00, I = 0%). In the subgroup analysis, the early clinical response rate at early clinical assessment and clinical response rate at test of cure of lefamulin was similar to that of moxifloxacin across different subgpopulations and all baseline CABP pathogens. Lefamulin was associated with a similar risk of adverse events as moxifloxacin.Clinical efficacy and tolerability for lefamulin in the treatment of CABP were similar to those for moxifloxacin.

Efficacy and Safety of Intravenous-to-oral Lefamulin, a Pleuromutilin Antibiotic, for the Treatment of Community-acquired Bacterial Pneumonia: The Phase III Lefamulin Evaluation Against Pneumonia (LEAP 1) Trial

BACKGROUND

Lefamulin, a pleuromutilin antibiotic, is active against pathogens commonly causing community-acquired bacterial pneumonia (CABP). The Lefamulin Evaluation Against Pneumonia (LEAP 1) study was a global noninferiority trial to evaluate the efficacy and safety of lefamulin for the treatment of CABP.

METHODS

In this double-blind study, adults with CABP of Pneumonia Outcomes Research Team risk class ≥III were randomized 1:1 to receive lefamulin at 150 mg intravenously (IV) every 12 hours or moxifloxacin at 400 mg IV every 24 hours. After 6 doses, patients could be switched to an oral study drug if prespecified improvement criteria were met. If methicillin-resistant Staphylococcus aureus was suspected, either linezolid or placebo was added to moxifloxacin or lefamulin, respectively. The US Food and Drug Administration primary endpoint was an early clinical response (ECR) 96 ± 24 hours after the first dose of the study drug in the intent-to-treat (ITT) population (noninferiority margin, 12.5%). The European Medicines Agency co-primary endpoints were an investigator assessment of clinical response (IACR) 5-10 days after the last dose of the study drug in the modified ITT (mITT) and clinically evaluable (CE) populations (noninferiority margin, 10%).

RESULTS

There were 551 patients randomized (n = 276 lefamulin; n = 275 moxifloxacin). Lefamulin was noninferior to moxifloxacin for ECR (87.3% vs 90.2%, respectively; difference -2.9%, 95% confidence interval [CI] g -8.5 to 2.8) and IACR (mITT, 81.7% vs 84.2%, respectively; difference -2.6%, 95% CI -8.9 to 3.9; CE, 86.9% vs 89.4%, respectively; difference -2.5%, 95% CI -8.4 to 3.4). Rates of study drug discontinuation due to treatment-emergent adverse events were 2.9% for lefamulin and 4.4% for moxifloxacin.

CONCLUSIONS

Lefamulin was noninferior to moxifloxacin for the primary efficacy endpoints and was generally safe and well tolerated.

CLINICAL TRIALS REGISTRATION

NCT02559310.

Pharmacokinetics and tolerability of lefamulin following intravenous and oral dosing

OBJECTIVES

To explore the pharmacokinetics (PK) of oral and intravenous (iv) lefamulin after single and multiple doses, and the effect of food on bioavailability.

METHODS

Lefamulin PK was examined in four studies. In Study 1, PK was assessed in patients with acute bacterial skin and skin structure infections who received repeated iv lefamulin q12h (150 mg). In Study 2, a four-period crossover study, healthy subjects received a single dose of oral lefamulin [immediate-release (IR) tablet, 1 × 600 mg] in a fasted and fed state, oral lefamulin (capsule, 3 × 200 mg) in a fasted state, and iv lefamulin in a fasted state. In Study 3, a three-period crossover study, healthy males received a single oral lefamulin dose (IR) in the following states: fasted, fasted followed by a high-calorie meal 1 h post-dose, and fed. Study 4 had two parts; in part A, healthy males received a single lefamulin dose (IR) in a fasted and fed state; in part B, subjects received repeated doses of lefamulin (IR, q12h) or placebo. Adverse events (AEs) were recorded in each study.

RESULTS

Single and repeated dosing of iv and oral lefamulin resulted in comparable exposure. Intravenous and oral lefamulin (given fasted or with a meal 1 h post-dose) resulted in bioequivalence. Bioequivalence was not established between oral lefamulin in the fed state and iv or oral administration in the fasted state. All AEs were mild or moderate in severity, no serious AEs were reported, and no participant discontinued because of an AE.

CONCLUSIONS

The PK of lefamulin supports successful switch from iv to oral therapy; lefamulin was generally well tolerated.

Pharmacokinetic/pharmacodynamic target attainment analyses to support intravenous and oral lefamulin dose selection for the treatment of patients with community-acquired bacterial pneumonia

OBJECTIVES

Lefamulin is a semi-synthetic intravenous (iv) and oral pleuromutilin antibiotic active against community-acquired bacterial pneumonia (CABP) pathogens. Pharmacokinetic/pharmacodynamic (PK/PD) target attainment analyses were carried out to evaluate lefamulin 150 mg iv q12h and 600 mg orally q12h under fed and fasted conditions for the treatment of patients with CABP.

METHODS

The analyses undertaken used a population PK model based on Phase 1 PK data, non-clinical PK/PD targets for efficacy and in vitro surveillance data for Streptococcus pneumoniae (SP) and Staphylococcus aureus (SA), and Monte Carlo simulation. Percentage probabilities of PK/PD target attainment by MIC on day 1 were determined using median total-drug epithelial lining fluid (ELF) and free-drug plasma AUC:MIC ratio targets associated with 1 and 2 log10 cfu reductions from baseline.

RESULTS

Percentage probabilities of attaining the total-drug ELF AUC:MIC ratio target for a 1 log10 cfu reduction from baseline for SP were ≥99.2% at the MIC90 of 0.12 mg/L and 96.7%, 82.1% and 96.3% for iv and oral dosing regimens under fed and fasted conditions, respectively, at the MIC99 of 0.25 mg/L. Percentage probabilities of attaining the free-drug plasma AUC:MIC target for the same endpoint at the SP MIC99 were 100% for each regimen. For the SA MIC90 of 0.12 mg/L and AUC:MIC ratio targets for the same endpoint, percentage probabilities were 92.7%-100% for iv and oral dosing regimens.

CONCLUSIONS

These data provide support for lefamulin 150 mg iv q12h and 600 mg orally q12h for the treatment of patients with CABP and suggest that doses may not need to be taken under fasted conditions.

Introduction: lefamulin and pharmacokinetic/pharmacodynamic rationale to support the dose selection of lefamulin

Lefamulin is the first semisynthetic pleuromutilin being developed for oral and intravenous administration. The drug selectively inhibits prokaryotic ribosomal protein synthesis by binding to the peptidyl transferase centre via four H-bonds and other interactions, resulting in an 'induced fit' that tightens the binding pocket around lefamulin. This unique mechanism of action has been associated with a low probability of cross-resistance to other antimicrobial classes commonly used to treat community-acquired bacterial pneumonia (CABP). This Supplement, entitled 'Pharmacokinetic and pharmacodynamic analyses and dose rationale for lefamulin, a novel pleuromutilin antibiotic, for the treatment of community-acquired bacterial pneumonia', is intended to be a valuable resource for both clinicians and researchers. It provides the essential pharmacokinetic and pharmacodynamic data on lefamulin that were used to support the optimal dose selection of lefamulin for the safe and effective treatment of CABP in adults.

Individualized treatment strategies for hyperuricemia informed by a semi-mechanistic exposure-response model of uric acid dynamics

To provide insight into pharmacological treatment of hyperuricemia we developed a semi-mechanistic, dynamical model of uric acid (UA) disposition in human. Our model represents the hyperuricemic state in terms of production of UA (rate, PUA), its renal filtration (glomerular filtration rate, GFR) and proximal tubular reabsorption (fractional excretion coefficient, FE). Model parameters were estimated using data from 9 Phase I studies of xanthine oxidase inhibitors (XOI) allopurinol and febuxostat and a novel uricosuric, the selective UA reabsorption inhibitor lesinurad, approved for use in combination with a XOI. The model was qualified for prediction of the effect of patients' GFR and FE on concentration of UA in serum (sUA) and UA excretion in urine and their response to drug treatment, using data from 2 Phase I and 4 Phase III studies of lesinurad. Percent reduction in sUA from baseline by a XOI is predicted to be independent of GFR, FE or PUA. Uricosurics are more effective in underexcreters of UA or patients with normal GFR. Co-administration of a XOI and an uricosuric agent should be considered for patients with high sUA first in the treatment algorithm of gout before uptitration of XOI. The XOI dose in combination with a uricosuric can be reduced compared to XOI alone for the same target sUA to the degree dependent on patient's GFR and FE. This exposure-response model of UA can be used to rationally select the best drug treatment option to lower elevated sUA in gout patients under differing pathophysiological situations.

Effects of Erdosteine on Experimental Acute Pancreatitis Model

OBJECTIVE

To create acute pancreatitis condition experimentally in rats using cerulein, and to reveal histopathological effects in pancreatic tissue with erdosteine.

STUDY DESIGN

An experimental study.

PLACE AND DURATION OF STUDY

Department of General Surgery, Duzce University, Turkey, from June to October 2014.

METHODOLOGY

Thirty male Wistar albino rats were divided into three groups. No procedures were applied to Group 1. The rats in Group 2 and Group 3 were injected cerulein, to establish an experimental pancreatitis model and the blood amylase and lipase values were examined. The rats in Group 3 were given 10 mg/kg erdosteine. This treatment was continued for another 2 days and the rats were sacrificed. The pancreatic tissues were examined histopathologically for edema, inflammation, acinar necrosis, fat necrosis, and vacuolization.

RESULTS

The lipase and amylase values and the histopathological examination of pancreatic tissues evidenced that the experimental acute pancreatitis model was established and edema, inflammation, acinar necrosis, fat necrosis, and vacuolization were observed in the pancreatic tissues. The statistical results suggest that erdosteine can decrease the edema, inflammation, acinar necrosis, fat necrosis and vacuolization scores in the tissues.

CONCLUSION

The severity of acute pancreatitis, induced by cerulein in rats, is reduced with the use of erdosteine.

Thymic E4bp4 gene transcription is up-regulated in the chicken during experimental peritonitis modified by the season-related lighting conditions

Immunity, like other vertebrate processes, undergoes the diurnal and seasonal rhythmicity generated and synchronized by the endogenous clock. In the present study a transcription of the selected clock genes was evaluated in the chicken thymus to verify its supposed role as a peripheral clock and to check its relation with the seasonality of immune function. Chickens kept from hatch in the season-related lighting conditions (LD 16:8 in summer vs 8:16 in winter) and in a controlled temperature were exposed to the experimental peritonitis elicited by i.p. thioglycollate injection. Previously described seasonality of the inflammatory response has been confirmed and the diurnal rhythms of a core clock gene Per3 and its repressor E4bp4 in the thymus has been evidenced. E4bp4 transcription was up-regulated in inflamed chickens while that of Per3 appeared independent of the locally induced inflammation. Our results suggest an interconnecting role of E4BP4 between molecular clock and immunity in the chicken.

Erdosteine reduces the exercise-induced oxidative stress in patients with severe COPD: Results of a placebo-controlled trial

BACKGROUND

Erdosteine (ER), a multimechanism, mucoactive agent with anti-oxidant and anti-inflammatory properties, has been shown to improve lung function, decrease plasma reactive oxygen species (ROS), and 8-isoprostane levels in patients with chronic obstructive pulmonary disease (COPD).

AIM

To assess vs. placebo the effect of ER on the exercise-induced oxidative stress by measuring and comparing the release of pro-inflammatory mediators in severe COPD patients.

METHODS

The double blind, placebo controlled study was carried out in 24 severe (GOLD Class III) COPD patients, aged >40 yr, randomized to receive either oral ER (600 mg/day, 8 males, mean age 70.5 yr) or placebo (9 males, mean age 70.8 yr) for 10 days. All patients performed a 6-min walking test (6MWT) before and after both treatments.

RESULTS

Mean ROS plasma levels increased significantly, but equally, in each group following the baseline 6MWT (p = ns). At the end of both treatments, a significant difference in mean plasma ROS increase from baseline became clear between the ER (+14.6% ± 2.7) and the placebo group (+24.4% ± 3.8) after the second 6MWT (p < 0.025). A similar significant trend was proved for the mean 8-isoprostane increase, which changed from baseline by +14.1% ± 2.6 in the ER, and by +26.3 ± 2.9 in the placebo group, respectively, after the second 6MWT (p < 0.006).

CONCLUSIONS

Data from the present study are suggesting that ER is effective in reducing the release of inflammatory mediators due to the exercise-induced oxidative stress in severe COPD patients.

Attenuation of bleomycin induced lung fibrosis by erdosteine and inhibition of the inducible nitric oxide synthase

BACKGROUND AND OBJECTIVES

Despite advances in treatment modalities, the discovery of optimal medical therapies still remains a necessity in the management of pulmonary fibrosis.

MATERIAL AND METHODS

The experiments were performed in 35 adult Sprague Dawley rats, randomly allotted into one of five groups (n=7). The control group was treated with 1 ml/kg, 0.9 % saline; the BLM group was given a single dose of BLM (2.5 U/kg); the BLM+ER group was treated with ER (10 mg/kg/day po) for 14 days after BLM administration; the BLM+SMT group was treated with i.p injections of SMT (20 mg/kg/ day) for 14 days after BLM administration; the BLM+ER+SMT group was treated with ER and SMT for 14 days after BLM administration. At the end of day 14, the results of histopathological, biochemical, and immunohistochemical investigations were analyzed.

RESULTS

Serum TNF-α, nitrate/nitrite, and TBARS levels significantly increased in BLM group compared to control group (p < 0.001, p < 0.001 and p < 0.05 respectively). Lung tissue content of IL-6 was found to be lower in BLM+ER, BLM+SMT and BLM+ER+SMT groups compared to BLM group by immunhistochemical examinations (p < 0.01, p < 0.01 and p < 0.001, respectively). Similarly, the TNF-α reactions (p < 0.01 for each group) and NF-kB expressions were shown to be significantly different among the study groups (p < 0.05, p < 0.05 and p < 0.001, respectively).

CONCLUSION

Based on our study, ER and SMT attenuate BLM-induced pulmonary fibrosis; the combination of two agents has a greater protective efficacy against fibrosis than one alone, reducing the inflammatory markers (Tab. 2, Fig. 2, Ref. 31).

A novel small-molecule inhibitor of mcl-1 blocks pancreatic cancer growth in vitro and in vivo

Using a high-throughput screening (HTS) approach, we have identified and validated several small-molecule Mcl-1 inhibitors (SMI). Here, we describe a novel selective Mcl-1 SMI inhibitor, 2 (UMI-77), developed by structure-based chemical modifications of the lead compound 1 (UMI-59). We have characterized the binding of UMI-77 to Mcl-1 by using complementary biochemical, biophysical, and computational methods and determined its antitumor activity against a panel of pancreatic cancer cells and an in vivo xenograft model. UMI-77 binds to the BH3-binding groove of Mcl-1 with Ki of 490 nmol/L, showing selectivity over other members of the antiapoptotic Bcl-2 family. UMI-77 inhibits cell growth and induces apoptosis in pancreatic cancer cells in a time- and dose-dependent manner, accompanied by cytochrome c release and caspase-3 activation. Coimmunoprecipitation experiments revealed that UMI-77 blocks the heterodimerization of Mcl-1/Bax and Mcl-1/Bak in cells, thus antagonizing the Mcl-1 function. The Bax/Bak-dependent induction of apoptosis was further confirmed using murine embryonic fibroblasts that are Bax- and Bak-deficient. In an in vivo BxPC-3 xenograft model, UMI-77 effectively inhibited tumor growth. Western blot analysis in tumor remnants revealed enhancement of proapoptotic markers and significant decrease of survivin. Collectively, these promising findings show the therapeutic potential of Mcl-1 inhibitors against pancreatic cancer and warrant further preclinical investigations.

Increase in sialylation and branching in the mouse serum N-glycome correlates with inflammation and ovarian tumour progression

Ovarian cancer is the most lethal gynaecological cancer and is often diagnosed in late stage, often as the result of the unavailability of sufficiently sensitive biomarkers for early detection, tumour progression and tumour-associated inflammation. Glycosylation is the most common posttranslational modification of proteins; it is altered in cancer and therefore is a potential source of biomarkers. We investigated the quantitative and qualitative effects of anti-inflammatory (acetylsalicylic acid) and pro-inflammatory (thioglycolate and chlorite-oxidized oxyamylose) drugs on glycosylation in mouse cancer serum. A significant increase in sialylation and branching of glycans in mice treated with an inflammation-inducing compound was observed. Moreover, the increases in sialylation correlated with increased tumour sizes. Increases in sialylation and branching were consistent with increased expression of sialyltransferases and the branching enzyme MGAT5. Because the sialyltransferases are highly conserved among species, the described changes in the ovarian cancer mouse model are relevant to humans and serum N-glycome analysis for monitoring disease treatment and progression might be a useful biomarker.

[Simultaneous determination of erdosteine and its active metabolite in human plasma by liquid chromatography-tandem mass spectrometry with pre-column derivatization]

A sensitive, rapid and accurate liquid chromatography-tandem mass spectrometric (LC-MS/MS) method with pre-column derivatization was developed for the simultaneous determination of erdosteine and its thiol-containing active metabolite in human plasma. Paracetamol and captopril were chosen as the internal standard of erdosteine and its active metabolite, respectively. Aliquots of 100 microL plasma sample were derivatized by 2-bromine-3'-methoxy acetophenone, then separated on an Agilent XDB-C18 (50 mm x 4.6 mm ID, 1.8 microm) column using 0.1% formic acid methanol--0.1% formic acid 5 mmol x L(-1) ammonium acetate as mobile phase, in a gradient mode. Detection of erdosteine and its active metabolite were achieved by ESI MS/MS in the positive ion mode. The linear calibration curves for erdosteine and its active metabolite were obtained in the concentration ranges of 5-3 000 ng x mL(-1) and 5-10 000 ng x mL(-1), respectively. The lower limit of quantification of erdosteine and its active metabolite were both 5.00 ng x mL(-1). The pharmacokinetic results of erdosteine and its thiol-containing active metabolite showed that the area under curve (AUC) of the thiol-containing active metabolite was 6.2 times of that of erdosteine after a single oral dose of 600 mg erdosteine tables in 32 healthy volunteers, The mean residence time (MRT) of the thiol-containing active metabolite was (7.51 +/- 0.788) h, which provided a pharmacokinetic basis for the rational dosage regimen.

Effects of thioglycolic acid on in vivo oocytes maturation in mice

BACKGROUND

Thioglycolic acid (TGA) is widely used in the hairdressing industry, which mostly caters to women. Recently, TGA has been reported to impair several organs, especially reproductive ones such as testes and ovaries. The reproductive toxicity of TGA on females has become an issue that cannot be neglected.

METHODOLOGY/PRINCIPAL FINDINGS

In the present work, superovulated female mice were percutaneously treated with different doses of TGA (37.81, 75.62, and 151.25 mg/kg). The mice were sacrificed to collect ovulated oocytes, whose numbers were counted and compared. Immunofluorescence-stained oocytes were observed under a confocal microscope to investigate the effects of TGA on spindle morphology, distribution of cortical granules (CGs), and parthenogenetic activation. The number of ovulated oocytes was decreased by TGA. The ovulated oocytes in the 151.25 mg/kg TGA group were significantly less than in the control and in the 37.81 mg/kg TGA groups. The ovulated oocytes in the 75.62 mg/kg TGA group were less than in the 37.81 mg/kg dose group. Abnormal spindle configuration in vivo was also induced by TGA. The spindle areas in the 75.62 and 151.25 mg/kg TGA groups were significantly larger than in the control and 37.81 mg/kg TGA groups. The parthenogenetic activation of ovulated oocytes in vitro was inhibited as well. The percentage of activated oocytes in the 75.62 and 151.25 mg/kg TGA groups was significantly lower than in the control and 37.81 mg/kg TGA groups. The percentage in the 151.25 mg/kg TGA group was also less than in the 75.62 mg/kg group. CG distribution was not affected by TGA.

CONCLUSION

Mice were percutaneously treated with TGA. Consequently, the number of ovulated oocytes decreased, abnormal spindle configurations were induced, and the parthenogenetic activation of ovulated oocytes was inhibited. CG distribution was not affected.

Nanoparticles of glycol chitosan and its thiolated derivative significantly improved the pulmonary delivery of calcitonin

A novel thiomer derivative of glycol chitosan (GCS) was synthesized by coupling with thioglycolic acid (TGA) and evaluated for the pulmonary delivery of peptides. Nanoparticles (NPs) based on GCS and GCS-TGA were obtained by the ionic gelation method and demonstrated a particle size in the range of 0.23-0.33 microm with positive surface charge and high calcitonin entrapment. Fluorescent GCS-TGA NPs resulted in a 2-fold increase in mucoadhesion to lung tissue after intra-tracheal administration to rats as compared to non-thiolated NPs. Evaluation of pulmonary toxicity revealed the biocompatibility of the two nanoparticulate formulations with lung tissue. The efficacy of the prepared NPs to enhance the pulmonary absorption of peptides was evaluated after pulmonary administration to rats using a liquid micro-sprayer technique. Calcitonin-loaded GCS and GCS-TGA NPs resulted in a pronounced hypocalcemic effect for at least 12 and 24 h, and a corresponding pharmacological availability of 27 and 40%, respectively. These findings suggest that both GCS and its thiomer derivative are promising and safe carriers for pulmonary peptide delivery.

Maturation-induced down-regulation of MFG-E8 impairs apoptotic cell clearance and enhances endotoxin response

In sepsis, phagocytosis and the killing of bacteria by phagocytes are important. Similarly, the clearance of accumulating apoptotic cells is critical in maintaining normal immunity. Upon maturation, peritoneal macrophages (PM) become a major source of proinflammatory cytokines, while losing their efficacy of phagocytosis. However, the underlying mechanism remains unknown. Here we investigated the differential effects of apoptotic thymocytes (AoTC) on TNF-alpha release in immature thioglycolate-elicited PM (TGPM) and mature resident PM (RPM) in vitro by culturing them with or without AoTC and/or LPS. MFG-E8 expression was assessed using Western blotting and the ability to engulf AoTC was determined histologically. Cytokine secretion was measured by ELISA. MAP kinase phosphorylation was assessed using Western blotting. Mature RPM express <50% of TGPM MFG-E8 levels and have a 30% lower capacity to clear AoTC. The proinflammatory response (TNF-alpha release) to LPS is 5 times higher, and the capability to phagocytose is decreased along with further down-regulation of MFG-E8 after LPS-stimulation. RPMs also lack phagocytosis-induced inhibition of TNF-alpha release after LPS stimulation. LPS-induced phosphorylation of ERK1/2, p38 and JNK is more enhanced in RPM compared to TGPM. MFG-E8-mediated apoptotic cell phagocytosis results in an inhibition of MAPK and NFkappaB signaling pathways. Differential MAPK activation may play a role in the enhanced LPS responsiveness of RPM and the lack of MFG-E8 impedes post-phagocytic suppression of LPS-response through the inhibition of those signaling pathways. These results provide a potential mechanistic insight into the benefit of promoting apoptotic cell clearance via MFG-E8 under inflammatory conditions.

The effects of erdosteine, N-acetylcysteine and vitamin E on nicotine-induced apoptosis of cardiac cells

This study was conducted to investigate the frequency of apoptosis in rat cardiomyocytes after intratraperitoneal nicotine injection, in order to examine the roles of inflammatory markers [myeloperoxidase (MPO) and tumor necrosis factor alpha (TNF-alpha)] in nicotine-induced cardiac damage and to determine the protective effects of three known antioxidant agents (N-acetylcysteine (NAC), erdosteine and vitamin E) on nicotine toxicity in the heart. Female Wistar rats were divided into seven groups, each composed of nine rats: two negative control groups, two positive control groups, one erdosteine-treated group (500 mg kg(-1)), one NAC-treated group (500 mg kg(-1)) and one vitamin E-treated group (500 mg kg(-1)). Nicotine was intraperitoneally injected at a dosage of 0.6 mg kg(-1) for 21 days. Following nicotine injection, the antioxidants were administered orally; treatment was continued until the rats were killed. Heart tissue samples were stained with hematoxylin-eosin for histopathological assessments. Apoptosis level in cardiomyocytes was determined by using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick endlabelling) method. Staining of cytoplasmic TNF-alpha in cardiomyocytes and heart MPO activity were evaluated by immunohistochemistry. The treatments with erdosteine, NAC and vitamin E significantly reduced the rate of nicotine-induced cardiomyocyte apoptosis. The effect of vitamin E on apoptosis regulation was weaker than the effects of erdosteine and NAC. Erdosteine, NAC and vitamin E significantly reduced the increases in the local production of TNF-alpha and heart MPO activity. This findings suggest that the effects of erdosteine and NAC on apoptosis regulation are stronger than that of vitamin E.

Ligation of CD200R by CD200 is not required for normal murine myelopoiesis

CD200R is an inhibitory receptor involved in the regulation of myeloid cells. It recruits Dok-1 and Dok-2, which are potent inhibitors of the Ras signalling pathway used by colony-stimulating factor (CSF) receptors. Dok-1/Dok-2 double knockout (DKO) mice develop leukaemia at 10-12 months of age. We investigated whether disturbed CD200R signalling could be responsible for this phenotype. Therefore, we studied whether CD200(-/-) mice have altered myelopoiesis and develop leukaemia. We report that CD200R is expressed on haematopoietic progenitor cells. However, CD200(-/-) mice have normal numbers of myeloid progenitors in the bone marrow and these cells have normal proliferative capacity. These results indicate that the development of leukaemia in Dok-1/Dok-2 DKO mice is not solely due to an absence of CD200R signalling. In addition, we show that the previously reported enhanced numbers of myeloid cells do not occur in all CD200(-/-) mice. We determined whether variations in the numbers of peripheral myeloid cells were due to an enhanced response to granulocyte-CSF (G-CSF) or an inflammatory stimulus. Mobilisation of immature neutrophils via G-CSF and infiltration of mature neutrophils and macrophages upon thioglycolate injection were not altered in CD200(-/-) mice. We conclude that CD200(-/-) mice exhibit normal myelopoiesis and that development of leukaemia in Dok-1/Dok-2 DKO mice is not caused by a lack of CD200-mediated CD200R signalling.

Protective effects of erdosteine on doxorubicin-induced hepatotoxicity in rats

BACKGROUND

Oxidative stress has an important role in the pathogenesis of doxorubicin-induced hepatotoxicity. The aim of this study was to investigate the hepatoprotective effects of erdosteine, an antioxidant agent, on doxorubicin-induced hepatotoxicity.

METHODS

Rats were divided into control, doxorubicin alone (20 mg/kg, i.p.) and doxorubicin plus erdosteine (50 mg/kg/day, oral) groups. At the end of the 10(th) day, liver tissues were removed for light microscopy and analysis. The levels of tissue protein carbonyl content, malondialdehyde and nitric oxide, as well as the activities of superoxide dismutase, catalase, were determined.

RESULTS

The tissue of the doxorubicin group showed some histopathological changes such as necrosis, hepatocyte degeneration, sinusoidal dilatation, hemorrhage and vascular congestion and dilatation. In the doxorubicin plus erdosteine group, histopathological evidence of hepatic damage was markedly reduced. Biochemical parameters were consistent with histological parameters.

CONCLUSIONS

Doxorubicin caused hepatotoxicity, and erdosteine treatment prevented lipid peroxidation and protein oxidant in liver tissue.

Mercaptoacetate fails to block the feeding-inhibitory effect of the β3-adrenergic receptor agonist CGP 12177A

Peripherally administered beta3-adrenergic receptor (beta3-AR) agonists stimulate lipolysis and inhibit food intake. To test the hypothesis that this inhibition of feeding is due to a substrate-driven increase in hepatic fatty acid oxidation (FAO), we assessed the ability of the FAO inhibitor mercaptoacetate (MA) to reverse the feeding-inhibitory effect of the beta3-AR agonist CGP 12177A (CGP). Adult male Sprague-Dawley rats received intraperitoneal injections of 1 mg/kg CGP, of 45.6 mg/kg MA, or of both drugs, and the effects on food intake, plasma free fatty acids (FFA), and plasma beta-hydroxybutyrate (BHB), an indicator for hepatic FAO, were assessed. Control rats received saline injections. CGP significantly reduced food intake after 0.5 and 6 h and increased plasma FFA and BHB at 0.5 h, suggesting increased lipolysis and hepatic FAO. MA completely reversed the increase in plasma BHB and thus appeared to effectively abolish CGP's effect on hepatic FAO, but MA failed to affect CGP's feeding-inhibitory action. These findings do not support the hypothesis that the beta3-AR agonist CGP inhibits feeding by enhancing hepatic FAO or ketogenesis. Although the beta3-AR agonist CGP reduced saccharin intake in a one-bottle condition taste aversion test, it seems unlikely that the hypophagic effect of CGP is elicited by malaise.

Thiolated chitosan nanoparticles enhance anti-inflammatory effects of intranasally delivered theophylline

Background

Chitosan, a polymer derived from chitin, has been used for nasal drug delivery because of its biocompatibility, biodegradability and bioadhesiveness. Theophylline is a drug that reduces the inflammatory effects of allergic asthma but is difficult to administer at an appropriate dosage without causing adverse side effects. It was hypothesized that adsorption of theophylline to chitosan nanoparticles modified by the addition of thiol groups would improve theophylline absorption by the bronchial epithelium and enhance its anti-inflammatory effects.

Objectives

We sought to develop an improved drug-delivery matrix for theophylline based on thiolated chitosan, and to investigate whether thiolated chitosan nanoparticles (TCNs) can enhance theophylline's capacity to alleviate allergic asthma.

Methods

A mouse model of allergic asthma was used to test the effects of theophylline in vivo. BALB/c mice were sensitized to ovalbumin (OVA) and OVA-challenged to produce an inflammatory allergic condition. They were then treated intranasally with theophylline alone, chitosan nanoparticles alone or theophylline adsorbed to TCNs. The effects of theophylline on cellular infiltration in bronchoalveolar lavage (BAL) fluid, histopathology of lung sections, and apoptosis of lung cells were investigated to determine the effectiveness of TCNs as a drug-delivery vehicle for theophylline.

Results

Theophylline alone exerts a moderate anti-inflammatory effect, as evidenced by the decrease in eosinophils in BAL fluid, the reduction of bronchial damage, inhibition of mucus hypersecretion and increased apoptosis of lung cells. The effects of theophylline were significantly enhanced when the drug was delivered by TCNs.

Conclusion

Intranasal delivery of theophylline complexed with TCNs augmented the anti-inflammatory effects of the drug compared to theophylline administered alone in a mouse model of allergic asthma. The beneficial effects of theophylline in treating asthma may be enhanced through the use of this novel drug delivery system.

Local amplification of glucocorticoids by 11 beta-hydroxysteroid dehydrogenase type 1 promotes macrophage phagocytosis of apoptotic leukocytes

Glucocorticoids promote macrophage phagocytosis of leukocytes undergoing apoptosis. Prereceptor metabolism of glucocorticoids by 11beta-hydroxysteroid dehydrogenases (11beta-HSDs) modulates cellular steroid action. 11beta-HSD type 1 amplifies intracellular levels of active glucocorticoids in mice by reactivating corticosterone from inert 11-dehydrocorticosterone in cells expressing the enzyme. In this study we describe the rapid (within 3 h) induction of 11beta-HSD activity in cells elicited in the peritoneum by a single thioglycolate injection in mice. Levels remained high in peritoneal cells until resolution. In vitro experiments on mouse macrophages demonstrated that treatment with inert 11-dehydrocorticosterone for 24 h increased phagocytosis of apoptotic neutrophils to the same extent as corticosterone. This effect was dependent upon 11beta-HSD1, as 11beta-HSD1 mRNA, but not 11beta-HSD2 mRNA, was expressed in these cells; 11-dehydrocorticosterone was ineffective in promoting phagocytosis by Hsd11b1(-/-) macrophages, and carbenoxolone, an 11beta-HSD inhibitor, prevented the increase in phagocytosis elicited in wild-type macrophages by 11-dehydrocorticosterone. Importantly, as experimental peritonitis progressed, clearance of apoptotic neutrophils was delayed in Hsd11b1(-/-) mice. These data point to an early role for 11beta-HSD1 in promoting the rapid clearance of apoptotic cells during the resolution of inflammation and indicate a novel target for therapy.

Erdosteine Against Acetaminophen Induced Renal Toxicity

Acetaminophen (APAP) induced toxicities have been a major problem in clinical practice. The aim of the present study was to demonstrate a possible protective role of erdosteine, a mucolytic agent having antioxidant properties via its active metabolites, on APAP induced renal damage in rats. Female Wistar Albino rats were divided into groups including control, erdosteine (150 mg/kg, oral), APAP (1 g/kg, oral) APAP+erdosteine (150 mg/kg, oral) and APAP+erdosteine (300 mg/kg, oral). APAP treatment caused lipid peroxidation as well as high NO level in renal tissue. Also, APAP treated rats had decreased activities of CAT and GSH-Px, but not SOD. In addition, tubular epithelial degeneration, vacuolization and cell desquamation were clearly observed in the APAP treated rats. The cellular debris in the proximal tubules and cortical interstitial congestions were prominent in the kidneys of APAP treated rats. BUN and creatinine levels were increased after APAP administration. All these pathological changes were reversed after erdosteine treatments. Erdosteine treated APAP groups showed milder tubular degeneration, epithelial vacuolization in the proximal tubules, lesser cellular desquamation and better morphology when compared with APAP groups. In conclusion, erdosteine may be a choice of preventive treatment against APAP induced nephrotoxicity.

Differential effects of lipoprivation and food deprivation on chow and milk intake in 25- and 30-day-old rats

The effects of administration of mercaptoacetate (MA) and overnight food deprivation on intake of chow and milk diets were investigated in juvenile rats. In rats aged 25 or 30 days, administration of mercaptoacetate-stimulated intake of rat chow, while either suppressing intake or not affecting intake of milk diets. These effects were observed when each diet was presented individually, and when animals had both diets simultaneously. In contrast, overnight food deprivation led to enhanced intake of both diets, whether presented individually or available simultaneously. These results suggest that by 25 days of age, rats acquire an adult-like increase in food intake following lipoprivation by administration of MA. However, the effects of MA on intake in animals at these ages depends on the diet offered.

Effect of crocin on experimental atherosclerosis in quails and its mechanisms

In the present study, we examined the prophylaxis effect of crocin on experimental atherosclerosis and its possible mechanisms. The atherosclerosis formation was induced by hyperlipidamic diet in quails. At the 9th week, serum lipid, MDA and NO were measured, and HE staining was used to investigate the histopathological changes of aorta. Bovine aortic endothelial cells (EC) were obtained from the thoracic aorta of newborn calves. After incubation of the cells with Ox-LDL (50 mg x L(-1)) for 24 h, the activities of LDH, NO in culture media and activity of NOS in endothelial cells were measured, flow cytometer was used to determine the rate of endothelial cells apoptosis. Peritoneal macrophages were obtained from thioglycolate-injected mice. Cholesterol and free cholesterol in cells were assayed after incubation of the cells with Ox-LDL. Bovine aortic smooth muscle cells (SMC) were obtained from the thoracic aorta of newborn calf. Proliferation was induced by 100 microg x L(-1) Ox-LDL and antiproliferative effect of crocin on SMCs were observed. SMCs cycle phases were measured by flow cytometry. SMCs were loaded with Fluo-3/AM and [Ca2+]i was measured by Laser Scanning Confocal Microscope (LSCM). Crocin could reduce the level of serum TC, TG, LDL-C and inhibit the formation of aortic plaque. Crocin could reduce MDA and inhibit the descending of NO in serum. Compared with control, Ox-LDL group could increase the activity of LDH and decrease activity of NO in culture media and activity of NOS in endothelial cells, preincubated with crocin, the effects of Ox-LDL were inhibited. Crocin could decrease the EC apoptosis induced by Ox-LDL. Crocin concentration-dependently inhibited the TC and CE elevation induced by Ox-LDL in macrophages. Crocin could inhibit the proliferation of SMCs induced by Ox-LDL. In the presence or absence of extracellular Ca2+, crocin concentration-dependently inhibited the [Ca2+]i elevation induced by 120 mg x L(-1)Ox-LDL, In the absence of extracellular Ca2+, crocin could inhibit the [Ca2+]i elevation induced by CHCl3 in a concentration-dependent manner. The results indicated that crocin could inhibit the formation of atherosclerosis in quails. Crocin had protective effects on endothelial cells. Crocin could decrease CE in macrophages and uptake of Ox-LDL, inhibiting the formation of foam cell, which would promote the initiation and progression of atherosclerosis. Crocin could inhibit the [Ca2+]i elevation in smooth muscle cell, Ca2+ is an important second messenger that regulates a variety of cellular processes, including smooth muscle cell proliferation and gene expression . Crocin exerted antiatherosclerotic effects through decreasing the level of Ox-LDL that plays an important role in the initiation and progression of atherosclerosis.

A Direct Role for C1 Inhibitor in Regulation of Leukocyte Adhesion

Plasma C1 inhibitor (C1INH) is a natural inhibitor of complement and contact system proteases. Heterozygosity for C1INH deficiency results in hereditary angioedema, which is mediated by bradykinin. Treatment with plasma C1INH is effective not only in patients with hereditary angioedema, but also in a variety of other disease models, in which such therapy is accompanied by diminished neutrophil infiltration. The underlying mechanism has been explained primarily as a result of the inhibition of the complement and contact systems. We have shown that C1INH expresses the sialyl-Lewis(x) tetrasaccharide on its N-linked glycan, via which it binds to E- and P-selectins and interferes with leukocyte-endothelial adhesion in vitro. Here we show that both native C1INH and reactive center cleaved C1INH significantly inhibit selectin-mediated leukocyte adhesion in several in vitro and in vivo models, whereas N-deglycosylated C1INH loses such activities. The data support the hypothesis that C1INH plays a direct role in leukocyte-endothelial cell adhesion, that the activity is mediated by carbohydrate, and that it is independent of protease inhibitory activity. Direct involvement of C1INH in modulation of selectin-mediated cell adhesion may be an important mechanism in the physiologic suppression of inflammation, and may partially explain its utility in therapy of inflammatory diseases.

Attenuation of bleomycin-induced lung fibrosis by oral sulfhydryl containing antioxidants in rats: erdosteine and N-acetylcysteine

Antioxidant therapy may be useful in diseases with impaired oxidant antioxidant balance such as lung fibrosis. The effects of sulfhydryl-containing antioxidant agents N-acetylcysteine (NAC) and erdosteine on the bleomycin-induced lung fibrosis were compared in rats. The animals were divided into four groups: Vehicle + vehicle, vehicle + bleomycin (2.5 U/kg), bleomycin + (10 mg/kg), and bleomycin + NAC (3 mmol/kg). Bleomycin administration resulted in prominent lung fibrosis as measured by lung hydroxyproline content and lung histology which is almost completely prevented by erdosteine and NAC. Hydroxyproline content was 18.7 +/- 3.5 and 11.2 +/- 0.6 mg/g dried tissue in bleomycin and saline treated rats, respectively (P < 0.001), and this level was 11.3 +/- 1.2 and 13.8 +/- 1.2 mg/g dried tissue in erdosteine and NAC pretreated, respectively. Erdosteine and NAC significantly reduced depletion of glutathione peroxidase, and prevented increases in myeloperoxidase activities, nitric oxide, and malondialdehyde levels in lung tissue produced by bleomycin. Data presented here indicate that erdosteine and NAC similarly prevented bleomycin-induced lung fibrosis and their antioxidant effects were also similar in this experiment.

The protective effect of erdosteine against ototoxicity induced by cisplatin in rats

The elimination of cisplatin ototoxicity is an ongoing concern. This experimental study was undertaken to investigate the effect of oral erdosteine in ameliorating cisplatin-induced ototoxicity. Twenty-eight adult female Wistar albino rats were randomly divided into four equal groups. Group A received an oral carrier vehicle of the drug erdosteine with 0.2 ml of 0.9% saline. Group B was administered only erdosteine (per oral 10 mg/kg twice a day) for 6 days. Group C was injected with cisplatin intraperitoneally (i.p.) on day 0 (16 mg/kg body weight), once only. Group D was given erdosteine (per oral 10 mg/kg/day) 1 day before and for 5 days consecutively after cisplatin injection (16 mg/kg, i.p.). Distortion product otoacoustic emissions (DPOAEs) were elicited in different frequency regions, ranging from 1,001 to 6,299 Hz as DPgram and input/output (I/O) functions from the control and experimental animals. All experimental animals were killed under general anesthesia on day 5, following the last otoacoustic emission measurements. Prior to death, blood samples were drawn for measurement of superoxide dismutase, xanthine oxidase (XO), malondialdehyde and nitric oxide. Initial DPgram and I/O function baseline measurements were similar in all groups prior to any drug administration ( P>0.05). On day 5, intra-subject measurement parameters of DPgrams and I/O functions in the cisplatin group showed significant deterioration ( P <0.05). The other groups revealed no differences between their pre- and post-test drug administration DPgrams and I/O functions at any test frequency ( P>0.05). Comparison of the amplitudes of DPgrams and I/O functions between the cisplatin and control groups showed significant changes ( P <0.05). Biochemical studies noted an increased XO activity following cisplatin administration ( P <0.007). The other biochemical results did not show significant differences between the study and control groups. This study demonstrates that, in rats, erdosteine is protective for cochlear function against the disruptive effects of cisplatin as measured by DPOAEs.

Modulation of lymphocyte proliferation by macrophages and macrophages loaded with arachidonic acid

Arachidonic acid (AA) is incorporated and exported by macrophages. This fatty acid is also transferred from macrophages (Mphi) to lymphocytes (LY) in co-culture. This observation led us to investigate the effect of macrophages pre-loaded with AA on concanavalin A (Con A)-stimulated lymphocyte proliferation. The experiments were performed in co-culture. This condition reproduces the in vivo microenvironment in which the modulation of lymphocyte proliferation is dependent on the interaction with macrophages. Lymphocytes obtained from untreated rats or from intraperitoneally thioglycolate-injected rats (THIO-treated) were co-cultured with macrophages from the same rats. Firstly, macrophages were co-cultured for 48 h with Con A-stimulated lymphocytes in different proportions: 0.5, 1, 2.5, 5, 10, 20 and 30% of 5 x 10(5) lymphocytes per well. At 1% proportion, macrophages caused maximum stimulation of lymphocyte proliferation; a four- to five-fold increase, for cells from both thioglycolate-treated and untreated rats, respectively, whereas at 20% it caused maximum inhibition. In addition, 1 or 20% macrophages were pre-loaded with several AA concentrations during a period of 6 h and co-cultured with lymphocytes. At 180 microM AA and 1% macrophages, lymphocyte proliferation was inhibited (by 25%), whereas at 20% macrophages, proliferation was increased, by 25- and three-fold, respectively, for cells from untreated and THIO-treated rats. AA added directly to the medium reduced lymphocyte proliferation, also being toxic to these cells at 100 microM. No toxic effects of AA were observed on macrophages. Additional evidence suggests that nitric oxide production is involved in the modulation of lymphocyte proliferation by AA-pre-loaded macrophages. These findings support the proposition that AA can directly modulate lymphocyte proliferation and the interaction between macrophages and lymphocytes.

Cisplatin-induced acute renal failure is ameliorated by erdosteine in a dose-dependent manner

The aim of this study was to investigate the optimum dosage of erdosteine to ameliorate cisplatin-induced nephrotoxicity. Three different doses of erdosteine at 25, 50 and 75 mg kg(-1) were studied in rats. Intraperitoneal administration of 7 mg kg(-1) cisplatin led to acute renal failure, as indicated by kidney histology and increases in plasma creatinine and blood urea nitrogen (BUN) levels. At 5 days after cisplatin injection the BUN level was increased significantly from 15.1 +/- 4.3 to 126.7 +/- 152.6 mg dl(-1) and plasma creatinine levels increased from 0.37 +/- 0.005 to 1.68 +/- 1.9 mg dl(-1). When the rats were administered 50 and 75 mg kg(-1) erdosteine 24 h before cisplatin injection that was continued until sacrifice (total of 6 days), the BUN and creatinine levels remained similar to control levels and the grade of histology was similar. Erdosteine at doses of 50 and 75 mg kg(-1) ameliorates cisplatin-induced renal failure. The optimum dose of erdosteine may be 50 mg kg(-1) in this study.

The Class A Macrophage Scavenger Receptor Attenuates CXC Chemokine Production and the Early Infiltration of Neutrophils in Sterile Peritonitis

The macrophage scavenger receptor (SR-A) is a multifunctional receptor that is associated with several important pathological conditions, including atherosclerosis. In this study, we show, using a sterile peritonitis model, that it can regulate the inflammatory response. SR-A null mice display an increased initial granulocytic infiltration because of overproduction of the CXC chemokines, MIP-2 and keratinocyte-derived cytokine. This differential response is dependent upon particle internalization and can be mimicked by advanced glycation end product-BSA-conjugated latex beads. Thus SR-A is a nonactivating receptor, which is the first example of a pattern recognition receptor that serves to counter the activities of proinflammatory receptors and attenuates the production of specific chemokines to ensure an inflammatory response of the appropriate magnitude.

Platelet Endothelial Cell Adhesion Molecule Deficiency or Blockade Significantly Reduces Leukocyte Emigration in a Majority of Mouse Strains

PECAM is a molecule used specifically during the diapedesis step when neutrophils and monocytes leave the blood compartment. Anti-PECAM reagents, such as Abs and soluble fusion proteins, block diapedesis both in vivo and in vitro. However, the PECAM knockout mouse in C57BL/6 strain has no serious defects in most models of inflammation. We show in this study that the same PECAM knockout backcrossed into the FVB/n strain clearly has reduced leukocyte emigration in two models of inflammation. Furthermore, we show that anti-PECAM reagents can block leukocyte emigration in several other wild-type strains of mice like FVB/n, SJL, and the outbred strain Swiss Webster. This clearly shows that the C57BL/6 strain is uniquely able to compensate for the loss of PECAM function. Murine models of inflammatory disease that have been studied using C57BL/6 mice should be re-evaluated using FVB/n or other mouse strains to determine whether PECAM plays a role in those models.

Stimulus-Dependent Requirement for Granulocyte-Macrophage Colony-Stimulating Factor in Inflammation

Data from several inflammation/autoimmunity models indicate that GM-CSF can be a key inflammatory mediator. Convenient models in readily accessible tissues are needed to enable the GM-CSF-dependent cellular responses to be elaborated. In this study, we show that, in contrast to the response to the commonly used i.p. irritant, thioglycolate medium, an Ag-specific methylated BSA-induced peritonitis in GM-CSF(-/-) mice was severely compromised. The reduced response in the latter peritonitis model was characterized by fewer neutrophils and macrophages, as well as by deficiencies in the properties of the remaining macrophages, namely size and granularity, phagocytosis, allogeneic T cell triggering, and proinflammatory cytokine production. B1 lymphocytes were more evident in the GM-CSF(-/-) Ag-specific exudates, indicating perhaps that GM-CSF can act on a common macrophage-B1 lymphocyte precursor in the inflamed peritoneum. We propose that these findings contribute to our understanding of how GM-CSF acts as a proinflammatory cytokine in many chronic inflammatory/autoimmune diseases. Of general significance, the findings also indicate that the nature of the stimulus is quite critical in determining whether a particular inflammatory mediator, such as GM-CSF, plays a role in an ensuing inflammatory reaction.

The phenotype of inflammatory macrophages is stimulus dependent: implications for the nature of the inflammatory response

Many diseases are characterized by inflammatory reactions involving both the innate and adaptive arms of the immune system. Thioglycolate medium (TM) injection into the peritoneal cavity has long been used as a stimulus for eliciting inflammatory macrophages for study and for determining the importance of a particular mediator in inflammation. However, the response to this irritant may not be relevant to many inflammatory diseases. Therefore, we have developed an Ag-specific peritonitis model using methylated BSA (mBSA) as the stimulus. Priming mice intradermally with mBSA in adjuvant and boosting 14 days later, followed by an i.p. challenge with mBSA after an additional 7 days, led to an inflammatory reaction equivalent in magnitude to that induced with TM as judged by the number of exudate cells. The inflammatory macrophages elicited by the mBSA protocol differed, being smaller and less vacuolated than TM-elicited macrophages. Also, macrophages from 4-day mBSA-induced exudates expressed more MHC class II than TM-induced exudates, were able to stimulate allogeneic T lymphocytes, and upon in vitro stimulation with LPS secreted greater levels of IL-6 and IL-1beta. Macrophages from 4-day TM-induced exudates, on the other hand, expressed Ly6C and ER-MP58, immature myeloid markers. The inflammatory response elicited using the Ag mBSA may be more relevant for studying the inflammatory responses in many diseases, such as those of autoimmune origin and those involving an acquired immune response.

Erdosteine prevents doxorubicin-induced cardiotoxicity in rats

The clinical use of doxorubicin (Dxr) is limited by its cardiotoxic effects which are mediated by oxygen radicals. The purpose of this study was to investigate in vivo protective effects of erdosteine, an antioxidant agent because of its secondary active metabolites in vivo, against the cardiotoxicity induced by Dxr in rats. Three groups of male Sprague-Dawley rats (60 days old) were used. Group 1 was untreated group used as control; the other groups were treated with Dxr (single i.p. dosage of 20 mg kg(-1) b.wt.) or Dxr plus erdosteine (10 mg kg(-1) day(-1), orally), respectively. Erdosteine or oral saline treatment was done starting 2 days before Dxr for 12 days. The analyses were done at the 10th day of Dxr treatment. The protein carbonyl content, the activities of myeloperoxidase, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine kinase (CK) as well as heart rate and blood pressures were significantly increased in Dxr group in comparison with the other groups. However, pulse pressure was decreased in Dxr group. The body and heart weights were decreased in both Dxr administered groups in comparison with control group. Disorganization of myocardial histology, picnotic nuclei, edema, and increase in collagen content around vessels were seen in the slides of Dxr group, whereas normal myocardial microscopy was preserved in Dxr plus erdosteine group. Collectively, these in vivo hemodynamic, enzymatic and morphologic studies provide an evidence for a possible prevention of cardiac toxicity in Dxr-treated patients.

Activation of mast cells induced by agonists of proteinase-activated receptors under normal conditions and during acute inflammation in rats

Functions of thrombin as a modulator of inflammation and tissue repair are mediated by the proteinase-activated receptor (PAR) family. Some of these effects may be induced by activation of mast cells. To characterize the degranulation of rat peritoneal mast cells in response to PAR agonists, the effects of thrombin, trypsin and peptide agonists of PARs (PAR-AP, proteinase-activated receptor-activating peptides) on secretion were investigated. The release of beta-hexosaminidase by thrombin (0.01-1 microM) was concentration-dependent and mediated via PAR(1), as evidenced by cathepsin G (100 microM)-induced inactivation of PAR(1) and thrombin-stimulated PAR(1) desensitization. Trypsin (1 microM) accelerated histamine secretion. The PAR(1)-AP, TRAP (SFFLRN, 1-100 microM) and the PAR(2)-AP SLIGRL (5-100 microM) caused the release of histamine, and beta-hexosaminidase from inflammatory mast cells were obtained from a model of acute peritonitis in rats. Relative to the response to compound 48/80, the thrombin- and TRAP-induced release of beta-hexosaminidase was higher in inflammatory mast cells than in the control. This suggests that additional exposure of PAR(1) on mast cells to PAR agonists or an increase in PARs sensitivity to PAR agonists probably occurred during acute inflammation.

Developmental toxicity evaluation of sodium thioglycolate administered topically to Sprague-Dawley (CD) rats and New Zealand White rabbits

BACKGROUND

Sodium thioglycolate, which has widespread occupational and consumer exposure to women from cosmetics and hair-care products, was evaluated for developmental toxicity by topical exposure during the embryonic and fetal periods of pregnancy

METHODS

Timed-mated Sprague-Dawley rats (25/group) and New Zealand White (NZW) rabbits (24/group) were exposed to sodium thioglycolate in vehicle (95% ethanol:distilled water, 1:1) by unoccluded topical application on gestational days (GD) 6-19 (rats) or 6-29 (rabbits) for 6 hr/day, at 0, 50, 100, or 200 mg/kg body weight/day (rats) and 0, 10, 15, 25, or 65 mg/kg/day (rabbits). At termination (GD 20 rats; GD 30 rabbits), fetuses were examined for external, visceral, and skeletal malformations and variations.

RESULTS

In rats, maternal topical exposure to sodium thioglycolate, at 200 mg/kg/day (the highest dose tested) on GD 6-19, resulted in maternal toxicity, including reduced body weights and weight gain, increased relative water consumption and one death. Treatment-related increases in feed consumption and changes at the applicationsite occurred at all doses, in the absence of increased body weights or body weight change. Fetal body weights/litter were decreased at 200 mg/kg/day, with no other embryo/fetal toxicity and no treatment-related teratogenicity in any group. In rabbits, maternal topical exposure to sodium thioglycolate on GD 6-29 resulted in maternal dose-related toxicity at the dosing site in all groups; no maternal systemic toxicity, embryo/fetal toxicity, or treatment-related teratogenicity were observed in any group.

CONCLUSIONS

A no observed adverse effect level (NOAEL) was not identified for maternal toxicity in either species with the dosages tested. The developmental toxicity NOAEL was 100 mg/kg/day (rats) and > or = 65 mg/kg/day (rabbits; the highest dose tested). The clinical relevance of theses study results is uncertain because no data were available for levels, frequency, or duration of exposures in female workers or end users.

Lupus-prone mice have an abnormal response to thioglycolate and an impaired clearance of apoptotic cells

Deficiency of complement in humans and mice is associated with the development of lupus and with abnormal repair of inflammatory and immune complex-mediated tissue injury. Here we ask whether similar defects in the resolution of inflammation are found in mice prone to spontaneous lupus. We compared the response to an i.p. injection of thioglycolate between two lupus-prone strains (MRL/Mp and NZB/W) and two non lupus-prone strains of mice (C57BL/6 and BALB/c). In all four strains the influx of polymorphonuclear neutrophils (PMN) was similar. However, by 96 h clearance of PMN in the control strains was complete, whereas in the autoimmune-prone strains PMN were still detectable. The number of mononuclear cells recruited was markedly reduced in the lupus-prone strains compared with the controls, and their phenotype was different. The lupus-prone strains had significantly fewer elicited macrophages that were CD11b-high and Ly6C-negative. In lupus-prone mice at 24 h there was a significantly increased number of apoptotic PMN free in the peritoneum, accompanied by a reduced percentage of macrophages containing apoptotic bodies, suggesting a defect in their uptake. An impaired ability of resident peritoneal macrophages from lupus-prone mice to engulf apoptotic cells was demonstrated by in vivo and in vitro cell clearance assays. These observations indicate that lupus-prone strains have an abnormal inflammatory response to thioglycolate and an intrinsic impairment in apoptotic cell uptake. These findings have implications for the initiation of autoimmunity, as lupus autoantigens are expressed on dying cells, and impaired disposal of these could enhance the development of autoimmunity.

Effects of 2-mercaptoacetate on ingestive behavior in 18- and 21-day-old rats

Previous work has demonstrated that mercaptoacetate (MA), which interferes with oxidation of fatty acids, can produce increases in intake in both adult and preweanling rats between 12 and 15 days of age. In both pups and adults, the increased intake is related to a decrease in the latency to initiate intake, but the duration of the effects of MA and the effective doses of MA differ in young pups compared to adult rats. Thus, in the present experiments, we examined older pups to determine the effects of administration of MA on ingestive behavior and energy-related markers (blood glucose, free fatty acids, and beta-hydroxybutryrate levels and weight loss) during the weaning transition. Pups aged 18 or 21 days received an i.p. injection of a 0, 22.8, 45.6 or 68.4 mg/kg MA, and after 1 h consumed a milk diet from the floor of a test container. Unlike younger pups or adult rats, MA did not stimulate intake in 18- or 21-day-old pups in a 30 or 60 min test, instead, the higher doses significantly suppressed intake. In addition, while latency to initiate intake was not reduced, primarily due to the very short latencies observed in control pups, the duration of intake was decreased by the higher doses of MA. Finally, MA did produce changes in fatty acid oxidation in pups at both ages, but baseline levels of free fatty acids and beta-hydroxybutryrate differed across the ages, as did the pattern of changes produced by MA. The results suggest that in contrast to the effects observed in both younger pups and adult rats, during the early weaning period exogenous alterations of fatty acid oxidation fail to stimulate intake. In addition, similar to effects seen in young pups, high doses of MA can significantly suppress intake. These differences in responding to MA during the weaning period may reflect heightened sensitivity to similar signals produced endogenously as a result of developmental changes in diet and/or metabolism or may result from heightened sensitivity to aversive properties of administration of MA.

129X1/SvJ mouse strain has a novel defect in inflammatory cell recruitment

Vitamin D-binding protein (DBP) has been reported to contribute to innate immunity. To verify prior in vitro and cell-based observations supporting this role, we assessed the ability of a recently developed DBP-null mouse line to recruit neutrophils and macrophages to a site of chemical inflammation. The interrupted DBP allele had been generated by homologous recombination in 129X1/SvJ embryonic stem cells and these cells were subsequently used to generate a line of DBP(-/-) (null) mice. Initial studies revealed a marked defect in the ability of these DBP(-/-) mice to recruit cells to the peritoneum after localized thioglycolate injection. However, progressive outcrossing of the DBP(-/-) mice to the C57BL/6J strain, conducted to provide a uniform genetic background for comparison of DBP-null and control mice, resulted in a progressive increase in cell recruitment by the DBP(-/-) mice and a loss in their apparent recruitment defect when compared with the DPB wild-type controls. These data suggested that the observed recruitment phenotype initially attributed to the absence of DBP was not linked to the DBP locus, but instead reflected the underlying genetic composition of the 129X1/SvJ ES cells used for the initial DBP gene disruption. A profound cell recruitment defect was confirmed in the 129X1/SvJ mice by direct analysis. Each of three commonly used inbred lines was discovered to have a distinct level of cell recruitment to a uniform stimulus (C57BL/6J > BALB/c > CD1 > 129X1/SvJ). Thus, this study failed to support a unique role for DBP in cellular recruitment during a model inflammatory response. Instead, the data revealed a novel and profound defect of cell recruitment in 129X1/SvJ mice, the strain most commonly used for gene deletion studies.

Therapeutic potential of a novel synthetic selectin blocker, OJ-R9188, in allergic dermatitis

1. We investigated the ability of a newly synthesized sugar derivative, OJ-R9188, [N-(2-tetradecylhexadecanoyl)-O-(L-alpha-fucofuranosyl)-D-seryl]-L-glutamic acid 1-methylamide 5-L-arginine salt, to block binding of selectins to their ligands in vitro and inhibit the infiltration of leukocytes in vivo. 2. OJ-R9188 prevented the binding of human E-, P- and L-selectin-IgG fusion proteins to immobilized sialyl Lewis(x) (sLe(x))-pentasaccharide glycolipid, with IC(50) values of 4.3, 1.3, and 1.2 microM, respectively. 3. In a mouse model of thioglycollate-induced peritonitis, OJ-R9188 at 10 mg kg(-1), i.v. inhibited neutrophil accumulation in the peritoneal cavity. In the IgE-mediated skin reaction, OJ-R9188 at 3 and 10 mg kg(-1), i.v. significantly inhibited extravasation of neutrophils and eosinophils into the inflammatory sites and at 10 mg kg(-1), i.v. also inhibited infiltration caused by picryl chloride-induced delayed-type hypersensitivity in mice. These results suggest that OJ-R9188 may be a useful selectin blocker, with activity against human and mouse E-, P- and L-selectins in vitro and in vivo, and that blocking selectin-sLe(x) binding is a promising strategy for the treatment of allergic skin diseases.

The anti-inflammatory activities of cannabinoid receptor ligands in mouse peritonitis models

In this report, we describe experiments in which cannabinoid receptor ligands were evaluated for effects on the development of a peritoneal inflammation when elicited in mice with thioglycollate broth or staphylococcus enterotoxin A. The cannabinoid receptor agonists [(-)-11-hydoxy-Delta(8) tetrahydrocannabinol-dimethylheptyl] (HU-210) and [(R)-(+)-[2,3-dihydro-5-methyl-3-[(4-morpholinyl)methyl[pyrrolo[1,2,3-de]1,4-benzoxazin-6-yl](1-naphthalenyl) methanone] (WIN 55212-2) blocked the migration of neutrophils into the peritoneal cavity in response to these inflammatory stimuli. This effect was caused by a delay in the production of the neutrophil chemoattractants, KC and macrophage inflammatory protein-2. HU-210 and WIN 55212-2 blocked neutrophil chemokines and neutrophil migration whether administered subcutaneously (s.c.) or intracerebroventricularly (i.c.v.). Their modulatory effects on the inflammation were antagonized by centrally administered [N-(piperdin-1-yl)-5-(4-chloropheny)-1-(2,4-dichloropheny)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride] (SR141716A), a selective cannabinoid CB(1) receptor antagonist. This latter observation, and the ability of the cannabinoid receptor agonists to suppress the peritoneal inflammation at relatively low doses when administered i.c.v., indicated a role for central cannabinoid CB(1) receptors in the anti-inflammatory activities of HU-210 and WIN 55212-2. The cannabinoid receptor agonists had no effect on monocyte migration elicited by thioglycollate, despite their ability to suppress monocyte chemotactic protein-1 levels in lavage fluids. The cannabinoid CB(2) receptor antagonist, [N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl]5-(4-choro-3 methylphenyl)-1-(4-methylbenzyl)pyrazole-3-carboxamide] (SR144528) inhibited the peritoneal inflammation in a manner analogous to that of HU-210 and WIN 55212-2 when administered i.c.v., but it did not appear to act through central cannabinoid CB(1) receptors. The present results add to the body of literature indicating that cannabinoid receptor ligands have diverse anti-inflammatory properties.

Regulation of leukocyte recruitment by polypeptides derived from high molecular weight kininogen

Proteolytic cleavage of single-chain, high molecular weight kininogen (HK) by kallikrein releases the short-lived vasodilator bradykinin and leaves behind a two-chain, high molecular weight kininogen (HKa) reported to bind to the beta2-integrin Mac-1 (CR3, CD11b/CD18, alphaMbeta2) on neutrophils and exert antiadhesive properties by binding to the urokinase receptor (uPAR) and vitronectin. We define the molecular mechanisms for the antiadhesive effects of HK related to disruption of beta2-integrin-mediated cellular interactions in vitro and in vivo. In a purified system, HK and HKa inhibited the binding of soluble fibrinogen and ICAM-1 to immobilized Mac-1, but not the binding of ICAM-1 to immobilized LFA-1 (CD11a/CD18, alphaLbeta2). This inhibitory effect could be attributed to HK domain 5 and to a lesser degree to HK domain 3, consistent with the requirement of both domains for binding to Mac-1. Accordingly, HK, HKa, and domain 5 inhibited the adhesion of Mac-1 but not LFA-1-transfected K562 human erythroleukemic cells to ICAM-1. Moreover, adhesion of human monocytic cells to fibrinogen and to human endothelial cells was blocked by HK, HKa, and domain 5. By using peptides derived from HK domain 5, the sequences including amino acids H475-G497 (and to a lesser extent, G440-H455) were identified as responsible for the antiadhesive effect, which was independent of uPAR. Finally, administration of domain 5 into mice, followed by induction of thioglycollate-provoked peritonitis, decreased the recruitment of neutrophils by approximately 70% in this model of acute inflammation. Taken together, HKa (and particularly domain 5) specifically interacts with Mac-1 but not with LFA-1, thereby blocking Mac-1-dependent leukocyte adhesion to fibrinogen and endothelial cells in vitro and in vivo and serving as a novel endogenous regulator of leukocyte recruitment into the inflamed tissue.

IFN-gamma is effective in reducing infections in the mouse model of chronic granulomatous disease (CGD)

Chronic granulomatous disease (CGD) is a genetic disorder characterized by recurrent bacterial and fungal infections and tissue granuloma formation. CGD phagocytes are unable to generate superoxide because of mutations in any of four proteins of the phagocyte NADPH oxidase. Prophylactic recombinant human interferon-gamma (IFN-gamma) has been shown to reduce the frequency and severity of infections in CGD patients, but its mechanism(s) remains undefined, and its benefit has been questioned. We investigated the prophylactic effect of IFN-gamma in the mouse model of the major autosomal recessive (p47(phox)) form of CGD. In a prospective, randomized, placebo-controlled study, we compared IFN-gamma, 20,000 U administered subcutaneously (s.c.) three times weekly, to placebo in 118 p47(phox-/-) mice. By 6 weeks of study, there were 3 infections in the IFN-gamma group compared with 13 infections in the placebo group (77% reduction in infections, p<0.01). By 18 months of study, there were 7 infections in the IFN-gamma group compared with 18 infections in the placebo group (39% reduction in infections, p<0.01). Two animals receiving IFN-gamma had seizures after 7 months in the study. No other toxicities were observed. Peripheral blood phagocytes from IFN-gamma treated p47(phox-/-) mice produced no superoxide, excluding restoration of the oxidative burst as a mechanism for the IFN-gamma effect. There were no differences in either peritoneal macrophage nitrate production or thioglycollate-induced peritoneal exudate between treatment groups. This animal model demonstrates a prophylactic benefit of IFN-gamma similar to that seen in humans and provides an opportunity to investigate the mechanism(s) of action for IFN-gamma in CGD.

Generation and analysis of mice lacking the chemokine fractalkine

Fractalkine (CX(3)CL1) is the first described chemokine that can exist either as a soluble protein or as a membrane-bound molecule. Both forms of fractalkine can mediate adhesion of cells expressing its receptor, CX(3)CR1. This activity, together with its expression on endothelial cells, suggests that fractalkine might mediate adhesion of leukocytes to the endothelium during inflammation. Fractalkine is also highly expressed in neurons, and its receptor, CX(3)CR1, is expressed on glial cells. To determine the biologic role of fractalkine, we used targeted gene disruption to generate fractalkine-deficient mice. These mice did not exhibit overt behavioral abnormalities, and histologic analysis of their brains did not reveal any gross changes compared to wild-type mice. In addition, these mice had normal hematologic profiles except for a decrease in the number of blood leukocytes expressing the cell surface marker F4/80. The cellular composition of their lymph nodes did not differ significantly from that of wild-type mice. Similarly, the responses of fractalkine(-/-) mice to a variety of inflammatory stimuli were indistinguishable from those of wild-type mice.

Developmental toxicity of an octyltin stabilizer in NMRI mice

The octyltin stabilizer ZK 30.434 is a mixture of 80% dioctyltin diisooctylthioglycolate (DOTTG) and 20% of monooctyltin triisooctylthioglycolate (MOTTG) and is used as stabilizer for rigid polyvinylchloride (PVC) materials. One of the applications of such stabilized films is the packaging of foodstuffs. Exposure to humans occurs via migration of DOTTG/MOTTG from PVC materials. In the present study the developmental toxicity of DOTTG/MOTTG in NMRI mice was investigated. Dams were treated orally with doses of 20, 30, 45, 67, or 100 mg/kg/day DOTTG/MOTTG from gestation day 6 through 17 (plug = day 1). Resorption rates were significantly increased and fetal weights significantly reduced in the study group at the 2 highest doses. External anomalies, such as bent forelimbs, cleft palate, and exencephaly were reported in the group treated with 100 mg/kg/day DOTTG/MOTTG, with the 67-mg/kd dose also exhibiting a significant increase in cleft palate. Moreover, an increase in skeletal anomalies was reported in fetuses exposed to 100 mg/kg/day. The doses of 20, 30, and 45 mg/kg/day elicited a significant increase in supernumerary lumbar ribs. It can be concluded that DOTTG/MOTTG is embryo-fetotoxic and induces developmental effects. The study revealed the need for the establishment of different No-Observed Adverse Effect Levels (NOAEL) for the endpoints investigated.