Dapsone suppresses human neutrophil superoxide production and elastase release in a calcium-dependent manner

Evaluating the protective effect of dapsone on experimental osteoarthritis models induced by MIA in male rats

OBJECTIVES

Osteoarthritis, a degenerative condition that results in significant morbidity, is typically managed with treatments aimed at symptom relief rather than addressing the underlying degeneration. Dapsone, recognized for its anti-inflammatory, antioxidant, antiexcitotoxic, and antiapoptotic properties, has demonstrated promising effects in various neurodegenerative diseases. This study explores the potential of dapsone to mitigate articular destruction, inflammation, and pain in rat models of osteoarthritis.

METHODS

Osteoarthritis was induced in rats by injecting MIA into the right knee joint. Dapsone was then administered intraperitoneally at 5, 10, or 20 mg/kg every 2 days for 2 weeks. Behavioural tests were done on days 0, 7, and 14. On day 14, the articular cartilage was histologically analysed using H&E staining. Serum levels of NF-kB, IL-1β, and TNF-α were evaluated by ELISA.

RESULTS

Dapsone effectively reduces pain, inflammation, and articular cartilage damage in osteoarthritis. Specifically, it improves mechanical allodynia and thermal hyperalgesia, reduces inflammatory markers (TNF-α, IL-1β, and NF-κB), and protects against cartilage destruction and chondrocyte loss, with the most significant effects at 20 mg/kg.

CONCLUSIONS

Dapsone effectively prevents pain, inflammation, and cartilage damage in osteoarthritis rats, suggesting its potential as a therapeutic option for managing osteoarthritis.

Investigating the efficacy of dapsone in treating sepsis induced by cecal ligation and puncture surgery in male mice

Sepsis is a life-threatening condition caused by the body's response to an infection. Dapsone is a sulfone with antibiotic properties, and experimental evidence suggests it has significant anti-inflammatory and anti-oxidative stress effects. The objective of this study was to investigate the efficacy of dapsone in mice after CLP (cecal ligation and puncture) surgery, which is a model for inducing sepsis. The study divided animals into five groups: CLP, sham, and three groups receiving different doses of dapsone (0.5, 1, 2 mg/kg). Sepsis was induced through CLP surgery, followed by dapsone administration. In each group, half of the mice were used to evaluate levels of various markers and pathological changes at 24 h post-CLP, while the other half was used to record the mortality rates within 96 h. The results showed that single-dose administration of dapsone at (0.5, 1, 2 mg/kg) after CLP surgery improved survival compared to the CLP group. Dapsone was also associated with a significant reduction in pro-inflammatory cytokines TNF-α, IL-1β, IL-6, NO, and MPO, as well as lactate and creatinine serum levels. However, dapsone did not have a significant effect on urea serum levels. In conclusion, the data suggest that dapsone treatment leads to increased survival in septic mice after CLP, and due to its ability to reduce TNF-α, IL-1β, IL-6, MPO, and lactate levels, it has anti-inflammatory effects in sepsis. The sepsis treatment with dapsone in mice protects against inflammation and oxidative stress.

Isobolographic Analysis of the Cytoprotective Effect of Dapsone and Cannabidiol Alone or Combination upon Oxygen-Glucose Deprivation/Reoxygenation Model in SH-SY5Y Cells

Oxidative stress and apoptosis cell death are critical secondary damage mechanisms that lead to losing neighboring healthy tissue after cerebral ischemia. This study aims to characterize the type of interaction between dapsone (DDS) and cannabidiol (CBD) and its cytoprotective effect in an in vitro model of oxygen and glucose deprivation for 6 h followed by 24 h of reoxygenation (OGD/R), using the SH-SY5Y cell line. For the combined concentrations, an isobolographic study was designed to determine the optimal concentration-response combinations. Cell viability was evaluated by measuring the lactate dehydrogenase (LDH) release and 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assays. Also, the reactive oxygen species (ROS) and reduced glutathione (GSH) levels were analyzed as oxidative stress markers. Finally, caspase-3 activity was evaluated as a marker cell death by apoptosis. The results showed a decrease in cell viability, an increase in oxidant stress, and the activity of caspase-3 by the effect of OGD/R. Meanwhile, both DDS and CBD demonstrated antioxidant, antiapoptotic, and cytoprotective effects in a concentration-response manner. The isobolographic study indicated that the concentration of 2.5 µM of DDS plus 0.05 µM of CBD presented a synergistic effect so that in treatment, cell death due to OGD/R decreased. The findings indicate that DDS-CBD combined treatment may be a helpful therapy in cerebral ischemia with reperfusion.

The Potential Effect of Dapsone on the Inflammatory Reactions in COVID-19: Staggering View

Severe SARS-CoV-2 infection is linked with an overstated immune response with the succeeding release of pro-inflammatory cytokines and progression of the cytokine storm. In addition, severe SARS-CoV-2 infection is associated with the development of oxidative stress and coagulopathy. Dapsone (DPS) is a bacteriostatic antibiotic that has a potent anti-inflammatory effect. Thus, this mini-review aimed to elucidate the potential role of DPS in mitigating inflammatory disorders in COVID-19 patients. DPS inhibits neutrophil myeloperoxidase, inflammation, and neutrophil chemotaxis. Therefore, DPS could be effective against neutrophilia-induced complications in COVID-19. In addition, DPS could be effective in mitigating inflammatory and oxidative stress disorders by suppressing the expression of inflammatory signaling pathways and the generation of reactive oxygen species (ROS) correspondingly. In conclusion, DPS might be effective in the management of COVID-19 through the attenuation of inflammatory disorders. Therefore, preclinical and clinical studies are reasonable in this regard.

Transient receptor potential vanilloid 4 (TRPV4) in neutrophils enhances myocardial ischemia/reperfusion injury

The Ca2+-permeable TRPV4 cation channel is expressed in neutrophils and contributes to myocardial ischemia/reperfusion injury. Here we tested the hypotheses that TRPV4 promotes neutrophil activation and subsequently aggregates myocardial ischemia/reperfusion injury. TRPV4 protein was confirmed in neutrophils, and its function was assessed by the current and intracellular Ca2+ concentration elevations evoked by TRPV4 agonists. Furthermore, TRPV4 agonists dose-dependently promoted migration toward fMLP, reactive oxygen species production, and myeloperoxidase release, which were prevented by pretreatment with a selective TRPV4 antagonist, in neutrophils from TRPV4 knockout mice, Ca2+-free medium, or BAPTA-AM + Ca2+-free medium. Blockade of TRPV4 also inhibited the effects of commonly used neutrophil activators fMLP and PMA. Mechanically, TRPV4 regulated neutrophil activation, particularly reactive oxygen species production, by affecting PKCα, P38, and AKT via Ca2+ signaling. In addition, isolated hearts infused with neutrophils from wild-type mice showed additional myocardial ischemia/reperfusion injuries but not those infused with TRPV4 knockout. Our study reveals that TRPV4-mediated neutrophil activation enhances myocardial ischemia/reperfusion injury, and it might be a novel therapeutic target for myocardial ischemia/reperfusion injury and other neutrophil-mediated inflammatory diseases.

Anti-Inflammatory Drug Therapy in Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis of Prospective Randomized and Placebo-Controlled Trials

Emerging evidence suggests that neuroinflammation may play a potential role in aneurysmal subarachnoid hemorrhage (aSAH). We aim to analyze the influence of anti-inflammatory therapy on survival and outcome in aSAH. Eligible randomized placebo-controlled prospective trials (RCTs) were searched in PubMed until March 2023. After screening the available studies for inclusion and exclusion criteria, we strictly extracted the main outcome measures. Dichotomous data were determined and extracted by odds ratio (OR) with 95% confidence intervals (CIs). Neurological outcome was graded using the modified Rankin Scale (mRS). We created funnel plots to analyze publication bias. From 967 articles identified during the initial screening, we included 14 RCTs in our meta-analysis. Our results illustrate that anti-inflammatory therapy yields an equivalent probability of survival compared to placebo or conventional management (OR: 0.81, 95% CI: 0.55-1.19, p = 0.28). Generally, anti-inflammatory therapy trended to be associated with a better neurologic outcome (mRS ≤ 2) compared to placebo or conventional treatment (OR: 1.48, 95% CI: 0.95-2.32, p = 0.08). Our meta-analysis showed no increased mortality form anti-inflammatory therapy. Anti-inflammatory therapy in aSAH patients tends to improve the neurological outcome. However, multicenter, rigorous, designed, prospective randomized studies are still needed to investigate the effect of fighting inflammation in improving neurological functioning after aSAH.

Gut Dysbiosis in Ocular Mucous Membrane Pemphigoid

Mucous Membrane Pemphigoid is an orphan multi-system autoimmune scarring disease involving mucosal sites, including the ocular surface (OcMMP) and gut. Loss of tolerance to epithelial basement membrane proteins and generation of autoreactive T cell and/or autoantibodies are central to the disease process. The gut microbiome plays a critical role in the development of the immune system. Alteration in the gut microbiome (gut dysbiosis) affects the generation of autoreactive T cells and B cell autoantibody repertoire in several autoimmune conditions. This study examines the relationship between gut microbiome diversity and ocular inflammation in patients with OcMMP by comparing OcMMP gut microbiome profiles with healthy controls. DNA was extracted from faecal samples (49 OcMMP patients, 40 healthy controls), amplified for the V4 region of the 16S rRNA gene and sequenced using Illumina Miseq platform. Sequencing reads were processed using the bioinformatics pipeline available in the mothur v.1.44.1 software. After adjusting for participant factors in the multivariable model (age, gender, BMI, diet, proton pump inhibitor use), OcMMP cohort was found to be associated with lower number of operational taxonomic units (OTUs) and Shannon Diversity Index when compared to healthy controls. Within the OcMMP cohort, the number of OTUs were found to be significantly correlated with both the bulbar conjunctival inflammation score (p=0.03) and the current use of systemic immunotherapy (p=0.02). The linear discriminant analysis effect size scores indicated that Streptococcus and Lachnoclostridium were enriched in OcMMP patients whilst Oxalobacter, Clostridia uncultured genus-level group (UCG) 014, Christensenellaceae R-7 group and butyrate-producing bacteria such as Ruminococcus, Lachnospiraceae, Coprococcus, Roseburia, Oscillospiraceae UCG 003, 005, NK4A214 group were enriched in healthy controls (Log10 LDA score < 2, FDR-adjusted p <0.05). In conclusion, OcMMP patients have gut dysbiosis correlating with bulbar conjunctival inflammation and the use of systemic immunotherapies. This provides a framework for future longitudinal deep phenotyping studies on the role of the gut microbiome in the pathogenesis of OcMMP.

Neuroprotective effect of dapsone in patients with aneurysmal subarachnoid hemorrhage: a prospective, randomized, double-blind, placebo-controlled clinical trial

OBJECTIVE

In this study, the authors sought to define the differences in the incidence of delayed cerebral ischemia (DCI) between patients treated with dapsone and those treated with placebo. Secondary objectives were to define the clinical outcome at discharge and 3 months and the incidence of brain infarction.

METHODS

A prospective, randomized, double-blind, placebo-controlled study was performed and included patients with aneurysmal subarachnoid hemorrhage (SAH) within 5 days from ictus who were candidates for aneurysm occlusion, and who had a Fisher grade of 3 or 4. Patients with sulfa or sulfone drug allergies, hemoglobin < 11 g/dl, known G6PD deficiency, and those refusing informed consent were excluded. A minimal relevant effect decrease of 35% in the incidence of DCI was established. Patients were randomly assigned to receive a regimen of dapsone 2.5 ml (100 mg) daily or a placebo (aluminum hydroxide suspension, 2.5 ml daily). Both groups received validated treatment for aneurysmal SAH. The appearance of DCI on CT was assessed in every patient at discharge and 3 months later. We used the chi-square test to compare the DCI incidence between both groups, and the Student t-test or nonparametric tests to compare quantitative variables.

RESULTS

Overall, 48 patients (70.8% women and 29.2% men) were included. The mean age was 50 years (SD 14.28 years, range 18-72 years). Prerandomization and postrandomization characteristics were balanced, except for the necessity of intra-arterial nimodipine administration in patients treated with placebo (15.4% vs 45.5%, p = 0.029. The incidence of DCI, the primary endpoint, for the whole cohort was 43.8% and was significantly lower in the dapsone group (26.9% vs 63.6%, p = 0.011). In addition, the irreversible DCI incidence was lower in the dapsone group (11.5% vs 54.5%, p = 0.12). A favorable modified Rankin Scale score was more frequent in the dapsone group at discharge and at 3 months (76.9% vs 36.4%, p = 0.005 and 80% vs 38.9%, p = 0.019, respectively). Also, the brain infarction incidence was lower in the dapsone group (19.2% vs 63.6%, p = 0.001). There was no difference between groups regarding adverse events.

CONCLUSIONS

Dapsone seems to play a role as a prophylactic agent in patients at high risk of developing DCI after aneurysmal SAH. A multicenter investigation is necessary to increase the study population and confirm the consistency of the results observed in this study.

Potential Role of CXCL10 in Monitoring Response to Treatment in Leprosy Patients

The treatment of multibacillary cases of leprosy with multidrug therapy (MDT) comprises 12 doses of a combination of rifampicin, dapsone and clofazimine. Previous studies have described the immunological phenotypic pattern in skin lesions in multibacillary patients. Here, we evaluated the effect of MDT on skin cell phenotype and on the Mycobacterium leprae-specific immune response. An analysis of skin cell phenotype demonstrated a significant decrease in MRS1 (SR-A), CXCL10 (IP-10) and IFNG (IFN-γ) gene and protein expression after MDT release. Patients were randomized according to whether they experienced a reduction in bacillary load after MDT. A reduction in CXCL10 (IP-10) in sera was associated with the absence of a reduction in the bacillary load at release. Although IFN-γ production in response to M. leprae was not affected by MDT, CXCL10 (IP-10) levels in response to M. leprae increased in cells from patients who experienced a reduction in bacillary load after treatment. Together, our results suggest that CXCL10 (IP-10) may be a good marker for monitoring treatment efficacy in multibacillary patients.

Dapsone Ameliorates Isoproterenol-Induced Myocardial Infarction via Nrf2/ HO-1; TLR4/ TNF-α Signaling Pathways and the Suppression of Oxidative Stress, Inflammation, and Apoptosis in Rats

Myocardial infarction (MI) is a critical condition that can happen with high doses or rapid termination of beta blockers therapy. The study aimed to evaluate the potential anti-toxic value of DAP against isoproterenol (ISO) - induced MI. Twenty-eight male Wistar rats were used for the study. The rodents were assigned to four groups (n = 7) and the treatments were given for 12 days as follows; Group 1 (control): were administrated normal saline, Group 2 (DAP control): were administrated DAP (10 mg/kg/day IP), Group 3 (ISO group): were administrated ISO (100 mg/kg, IP on the 11th and 12th days of the experiment), and Group 4 (DAP + ISO): co-treated with DAP plus ISO. The measured parameters were cardiac malondialdehyde (MDA), reduced glutathione (GSH), total nitrite/nitrate (NOx), catalase (CAT), serum cardiac biomarkers; CK-MB, ALT, LDH, and ALK-PH. Also, interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), heme oxygenase-1 (HO-1), toll-like receptor 4 (TLR4), caspase-3 activity, and hepatic BAX and Bcl-2 were also assessed. Also, histological examination and vimentin immuno-expressions were studied. ISO group exhibited MI as evidenced by the elevation in serum cardiac biomarkers, MDA, NOx, IL-1β, TNF-α, and caspase-3 together with the reduction in GSH, Nrf2, HO-1 levels, and a faint vimentin immuno-reaction. Histological alterations revealing distorted cardiomyocytes; vacuolation, edema, pyknosis, and fragmentation were also noticed. DAP significantly ameliorated all the examined toxicity indicators. DAP revealed efficient ameliorative actions against ISO-caused MI by marked reduction in myocardial infarct size and suppressed oxidative stress, inflammation, and apoptosis via the up-regulation of the Nrf2/HO-1; TLR4/TNF-α signaling pathways.

Antibiotics with therapeutic effects on spinal cord injury: a review

Accumulating evidence indicates that a considerable number of antibiotics exert anti-inflammatory and neuroprotective effects in different central and peripheral nervous system diseases including spinal cord injury (SCI). Both clinical and preclinical studies on SCI have found therapeutic effects of antibiotics from different families on SCI. These include macrolides, minocycline, β-lactams, and dapsone, all of which have been found to improve SCI sequels and complications. These antibiotics may target similar signaling pathways such as reducing inflammatory microglial activity, promoting autophagy, inhibiting neuronal apoptosis, and modulating the SCI-related mitochondrial dysfunction. In this review paper, we will discuss the mechanisms underlying therapeutic effects of these antibiotics on SCI, which not only could supply vital information for investigators but also guide clinicians to consider administering these antibiotics as part of a multimodal therapeutic approach for management of SCI and its complications.

Dapsone prolong delayed excitotoxic neuronal cell death by interacting with proapoptotic/survival signaling proteins

BACKGROUND

Dapsone prevents ischemic injury, inhibits apoptosis and shows functional improvement post-ischemia. However, its effect on proapoptotic or survival proteins in delayed ischemia remains unclear.

METHODS

Male adult Wistar rats were subjected to middle cerebral artery occlusion (MCAO) for 90 min followed by 24 h of ischemic reperfusion (I/R). Dapsone [9.375 or 12.5 mg/kg, intraperitoneally (IP)] was administered at 3, 6 and 12 h of I/R followed by behavioural assessment, brain infarction, histological alteration and cell viability study. Further, dapsone (25 and 50 µM) was added at 3, 6 and 12 h after L-glutamate (100 µM) in primary cortical culture (DIV 14) and cell viability, cytotoxicity, apoptosis was observed. Proteins expression were observed using immunocytochemistry. All experiments were performed after 24 h of I/R (In-Vivo) and 24 h of recovery post glutamate insult (In-Vitro).

RESULTS

Reduced brain infarction, improved neurobehavioural functions in addition to reduction in abnormal morphological structures of ischemic brain and improvement in cell viability was observed with treatment of dapsone (12.5 mg/kg) administered upto 6 h. Similarly, dapsone (25, 50 µM) increased cell survival post glutamate insult in cortical culture (In-vitro). Further, dapsone treatment at delayed hours (6 h) reduced apoptotic nuclei and proapoptotic proteins JNK, PTEN, Calpain, Caspase 3 expression along with activation of prosurvival protein BDNF expression post-glutamate insult.

CONCLUSION

Our results suggest that dapsone has the potential to limit the neuronal damage post-glutamate insult in delayed hours (6 h) through repressing proapoptotic proteins JNK, PTEN, Calpain, Caspase-3 of cerebral ischemia along with activation of pro-survival protein BDNF.

The effect of vehicle on skin absorption of Mg2+ and Ca2+ from thermal spring water

OBJECTIVE

Thermal spring waters (TSW) are commonly used as active ingredients in cosmetics. Their biological activities directly depend on the ionic composition of the spring. However, in order to exhibit beneficial properties, the minerals need to reach viable skin layers. The present study addresses the incorporation of marketed TSW in model cosmetic formulations and the impact of the formulation on skin absorption of magnesium and calcium ions that are known to improve skin barrier function.

METHODS

Marketed TSW was introduced into five formulations. Liposomes were prepared using saturated or unsaturated phospholipids mixed with cholesterol by the thin layer evaporation technique. Emulsions water-in-oil (W/O), oil-in-water (O/W) or double: water-in-oil-in-water (W/O/W) were prepared by high-shear mixing. Skin absorption of Mg²⁺ and Ca²⁺ from those formulations was studied in vitro using static Franz diffusion cells under infinite dose condition and under occlusion of the apparatus.

RESULTS

Mg²⁺ and Ca²⁺ penetrate skin samples from TSW. Encapsulating TSW into double emulsion (TSW/O/W) increased skin absorption of both cations of interest and kept the Ca²⁺ /Mg²⁺ ratio equal to that of TSW in each skin layer. The dermal absorption of Mg²⁺ from the double emulsion departs from both single emulsions. Application of liposome suspension improved the skin absorption of Ca²⁺ while keeping constant that of Mg²⁺ , leading to unbalanced Ca²⁺ /Mg²⁺ ratio inside skin.

CONCLUSION

The beneficial effects of TSW are not only due to their action on the skin surface. Their active components, especially Ca²⁺ and Mg²⁺ cations, reach viable skin layers in a formulation-dependent manner. The distribution of ions inside skin depends on the type of formulation.

Dual inhibition of complement factor 5 and leukotriene B4 synergistically suppresses murine pemphigoid disease

The treatment of most autoimmune diseases still relies on systemic immunosuppression and is associated with severe side effects. The development of drugs that more specifically abrogate pathogenic pathways is therefore most desirable. In nature, such specificity is exemplified, e.g., by the soft tick-derived biotherapeutic Coversin, which locally suppresses immune responses by inhibiting complement factor 5 (C5) and leukotriene B4 (LTB4). C5a, a proteolytic fragment of C5, and LTB4 are critical drivers of skin inflammation in pemphigoid diseases (PDs), a group of autoimmune blistering skin diseases. Here, we demonstrate that both Coversin and its mutated form L-Coversin, which inhibits LTB4 only, dose dependently attenuate disease in a model of bullous pemphigoid-like epidermolysis bullosa acquisita (BP-like EBA). Coversin, however, reduces disease more effectively than L-Coversin, indicating that inhibition of C5 and LTB4 synergize in their suppressing effects in this model. Further supporting the therapeutic potential of Coversin in humans, we found that C5a and LTB4 are both present in the blister fluid of patients with BP in quantities inducing the recruitment of granulocytes and that the number of cells expressing their receptors, C5aR1 and BLT1, respectively, is increased in perilesional skin. Collectively, our results highlight Coversin and possibly L-Coversin as potential therapeutics for PDs.

Colchicine plus Dapsone in Colchicine-Resistant FMF Patients

Five to ten percent of FMF patients have unfavorable response to the colchicine as a standard therapy. Biologic treatments have been shown to be highly effective, but there are often unavailable, because the price is unaffordably high. This study shows the striking effect of combined dapsone and colchicine therapy in such patients and recommends it as an alternative therapy in colchicine-resistant (CR) patients.

Imidazole alkaloids inhibit the pro-inflammatory mechanisms of human neutrophil and exhibit anti-inflammatory properties in vivo

OBJECTIVES

Epiisopiloturine (EPI) and epiisopilosine (EPIIS) are side products in the pharmaceutical industry. The present study aimed to investigate the anti-inflammatory potential of the alkaloids EPI and EPIIS in human neutrophils and mechanical hyperalgesia in mice.

METHODS

Neutrophils (5 × 10⁶  cells/ml) incubated with EPI and EPIIS and stimulated by the addition of N-formyl-methionyl-leucyl-phenylalanine or phorbol 12-myristate-13-acetate. The release of myeloperoxidase (MPO), reactive oxygen species (ROS) production, calcium influx, gene expression of NF-κB and pro-inflammatory cytokines production were evaluated. It was also investigated the effect these alkaloids on carrageenan-induced mechanical hyperalgesia model in mice.

KEY FINDINGS

We demonstrated that both EPI and EPIIS inhibited the degranulation of activated neutrophils. This effect was accompanied by the reduction in ROS, the prevention of the increase in intracellular Ca²⁺ and decrease in the density of cytosolic NF-κB, and inhibition of TNF-α and IL-6 production. Evaluating hypernociception in mice, EPI and EPIIS inhibited carrageenan-induced inflammatory hypernociception and reduced MPO levels.

CONCLUSIONS

The results obtained suggest EPI and EPIIS not only inhibit neutrophils functions in vitro, but also exhibits anti-inflammatory properties in vivo, acting through the modulation of the activation and/or accumulation of neutrophils in the inflammatory focus. Thus, EPI and EPIIS possess promising anti-inflammatory therapeutic potential.

The Efficacy and Mechanism Evaluation of Treating Idiopathic Pulmonary fibrosis with the Addition of Co-trimoxazole (EME-TIPAC): study protocol for a randomised controlled trial

BACKGROUND

We hypothesise, based upon the findings from our previous trial, that the addition of co-trimoxazole to standard therapy is beneficial to patients with moderate to severe idiopathic pulmonary fibrosis (IPF). We aim to investigate this by assessing unplanned hospitalisation-free survival (defined as time from randomisation to first non-elective hospitalisation, lung transplant or death) and to determine whether any effect relates to changes in infection and/or markers of disease control and neutrophil activity.

METHODS/DESIGN

The EME-TIPAC trial is a double-blind, placebo-controlled, randomised, multicentre clinical trial. A total of 330 symptomatic patients, aged 40 years old or older, with IPF diagnosed by a multidisciplinary team (MDT) according to international guidelines and a FVC ≤ 75% predicted will be enrolled. Patients are randomised equally to receive either two tablets of co-trimoxazole 480 mg or two placebo tablets twice daily over a median treatment period of 27 (range 12-42) months. All patients receive folic acid 5 mg daily whilst on the trial IMP to reduce the risk of bone marrow depression. The primary outcome for the trial is a composite endpoint consisting of the time to death, transplant or first non-elective hospital admission and will be determined from adverse event reporting, hospital databases and the Office of National Statistics with active tracing of patients missing appointments. Secondary outcomes include the individual components of the primary outcome, (1) King's Brief Interstitial Lung Disease Questionnaire, (2) MRC Dyspnoea Score, (3) EQ5D, (4) spirometry, (5) total lung-diffusing capacity and (6) routine sputum microbiology. Blood will be taken for cell count, biochemistry and analysis of biomarkers including C-reactive protein and markers of disease. The trial will last for 4 years. Recruitment will take place in a network of approximately 40 sites throughout the UK (see Table 1 for a full list of participating sites). We expect recruitment for 30 months, follow-up for 12 months and trial analysis and reporting to take 4 months.

DISCUSSION

The trial is designed to test the hypothesis that treating IPF patients with co-trimoxazole will increase the time to death (all causes), lung transplant or first non-elective hospital admission compared to standard care ( https://www.nice.org.uk/guidance/cg163 ), in patients with moderate to severe disease. The mechanistic aims are to investigate the effect on lung microbiota and other measures of infection, markers of epithelial injury and markers of neutrophil activity.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials Number (ISRCTN) Registry, ID: 17464641 . Registered on 29 January 2015.

Managing panniculitis in alpha-1 antitrypsin deficiency: Systematic review of evidence behind treatment

AIM

To systematically review literature for management of alpha-1 antitrypsin deficiency (AATD) panniculitis.

METHODS

Multiple databases were searched using combinations of pertinent terms. Articles were selected describing panniculitis treatment in patients with AAT < 11 μmol and/or PiZZ genotype, with no language limitation. All relevant articles were accessed in full text. Independent review of abstracts and full manuscripts was conducted by 2 reviewers, and quality assessment by one reviewer (checked by a second). Data extraction was conducted by one reviewer (checked by a second). Narrative synthesis only was conducted, as data were unsuitable for meta-analysis.

RESULTS

Thirty-two case reports and 4 case series were found. Augmentation therapy (infusions of plasma-derived AAT) was the most successful, with complete resolution of symptoms in all patients. Dapsone is a less expensive option, and it achieved clinical resolution in 62% of patients, but it is very poorly tolerated. Among other single-agent antibiotics, doxycycline was the most successful with complete clinical resolution seen in 33% of patients. Immunosuppressants were largely unsuccessful; 80% of patients exhibited no response. Liver transplantation and therapeutic plasma exchange displayed complete resolution in 66% of patients. Other strategies, such as non-steroidal anti-inflammatory drugs or antibiotics other than dapsone did not show sufficient response rates to recommend their use. Authors note the risk of bias imposed by the type of evidence (case reports, case series) available in this field.

CONCLUSION

Dapsone is the recommended first line therapy for AATD panniculitis, followed by augmentation therapy. Plasma exchange may be an alternative in the setting of rapidly progressive disease.

Linear immunoglobulin A/G bullous dermatosis associated with ulcerative colitis

Linear immunoglobulin (Ig)A/G bullous dermatosis (LAGBD) is an autoimmune bullous disease characterized by formation of subepidermal blisters and linear deposition of IgA and IgG antibodies along the basement membrane zone (BMZ). The association between linear IgA bullous dermatosis and ulcerative colitis (UC) is well recognized, but reports of UC-associated LAGBD are lacking. We have reported a 24-year-old man suffering from LAGBD associated with UC, which occurred before exacerbations of skin rash. A skin biopsy indicated a subepidermal blister with an infiltration of primarily neutrophils and eosinophils in the dermis. Direct immunofluorescence (IF) studies showed a linear deposition of IgA, IgG and C3c. Indirect IF of human skin revealed IgA and IgG anti-BMZ autoantibodies. Indirect IF of 1 M NaCl-split human skin demonstrated reactivity of IgA and IgG antibodies at the epidermal side. Immunoblotting showed that IgG antibodies reacted to the BP180 NC16a domain and 120-kDa linear IgA dermatosis-1, and enzyme-linked immunoassay detected IgG anti-BP230 antibodies. Administration of prednisolone and diaminodiphenyl sulfone (DDS) via the p.o. route improved skin lesions and bowel conditions. These results suggest that the bowel inflammation observed in UC may have a causative effect of initiation of the immune response to the skin and development of the bullous skin lesions in LAGBD. A combination of DDS and corticosteroid could be a recommended therapeutic option for patients with LAGBD with UC.

Cytokines as biomarkers to monitoring the impact of multidrug therapy in immune response of leprosy patients

Leprosy or Hansen's disease is a chronic infectious disease of the skin and nerves, caused by the intracellular bacilli Mycobacterium leprae. It is characterized by a spectrum of clinical forms depending on the host's immune response to M. leprae. Patients with tuberculoid (TT) leprosy have strong cell-mediated immunity (CMI) with elimination of the bacilli, whereas patients with lepromatous (LL) leprosy exhibit defective CMI to M. leprae. Despite advances in the understanding of the pathogenesis of leprosy and the development of new therapeutic strategies, there is a need for the identification of biomarkers which be used for early diagnosis and to discrimination between different forms of the disease, as prognostic markers. Here, we analyzed the serum levels of IL-1β, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-17A, IFN-γ and TNF in order to address the contribution of these cytokines in late phase of M. leprae infection, and the impact of multidrug therapy (MDT). Our results demonstrated that patients of LL group presented higher expression of serum levels of inflammatory cytokines before MDT, while TT patients presented a balance between inflammatory and regulatory cytokines. MDT changes the profile of serum cytokines in M. leprae infected patients, as evidenced by the cytokine network, especially in TT patients. LL patients displayed a multifaceted cytokine system characterized by strong connecting axes involving inflammatory/regulatory molecules, while TT patients showed low involvement of regulatory cytokines in network overall. Cytokines can be identified as good biomarkers of the impact of MDT on the immune system and the effectiveness of treatment.

Inhibition of neutrophil superoxide generation by shikonin is associated with suppression of cellular Ca(2+) fluxes

Shikonin, an anti-inflammatory compound of “Shikon”, inhibits the neutrophil superoxide (O₂^•−) generation by NADPH oxidase 2 (Nox2); however, the mechanisms of how shikonin affects Nox2 activity remained unclear. We aimed to elucidate the relationship between the inhibition of Nox2 activity and influences on intracellular Ca²⁺ concentration ([Ca²⁺]_i) by shikonin. For this purpose, we used a simultaneous monitoring system for detecting changes in [Ca²⁺]_i (by fluorescence) and O₂^•− generation (by chemiluminescence) and evaluated the effects of shikonin on neutrophil-like HL-60 cells stimulated with N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLP). Since fMLP activates Nox2 by elevation in [Ca²⁺]_i via fluxes such as inositol 1,4,5-trisphosphate-induced Ca²⁺ release (IICR) and store-operated Ca²⁺ entry (SOCE), we also evaluated the effects of shikonin on IICR and SOCE. Shikonin dose-dependently inhibited the fMLP-induced elevation in [Ca²⁺]_i and O₂^•− generation (IC₅₀ values of 1.45 and 1.12 µM, respectively) in a synchronized manner. Analyses of specific Ca²⁺ fluxes showed that shikonin inhibits IICR and IICR-linked O₂^•− generation (IC₅₀ values: 0.28 and 0.31 µM for [Ca²⁺]_i and O₂^•−, respectively), as well as SOCE and SOCE-linked O₂^•− generation (IC₅₀ values: 0.39 and 0.25 µM for [Ca²⁺]_i and O₂^•−, respectively). These results suggested that shikonin inhibits the O₂^•− generation by Nox2 in fMLP-stimulated neutrophils by targeting Ca²⁺ fluxes such as IICR and SOCE.

Mechanisms of autoantibody production in systemic lupus erythematosus

Autoantibodies against a panoply of self-antigens are seen in systemic lupus erythematosus, but only a few (anti-Sm/RNP, anti-Ro/La, anti-dsDNA) are common. The common lupus autoantigens are nucleic acid complexes and levels of autoantibodies can be extraordinarily high. We explore why that is the case. Lupus is associated with impaired central or peripheral B-cell tolerance and increased circulating autoreactive B cells. However, terminal differentiation is necessary for autoantibody production. Nucleic acid components of the major lupus autoantigens are immunostimulatory ligands for toll-like receptor (TLR)7 or TLR9 that promote plasma cell differentiation. We show that the levels of autoantibodies against the U1A protein (part of a ribonucleoprotein) are markedly higher than autoantibodies against other antigens, including dsDNA and the non-nucleic acid-associated autoantigens insulin and thyroglobulin. In addition to driving autoantibody production, TLR7 engagement is likely to contribute to the pathogenesis of inflammatory disease in lupus.

Blood-brain barrier dysfunction in mice induced by lipopolysaccharide is attenuated by dapsone

Blood-brain barrier (BBB) dysfunction is a key event in the development of many central nervous system (CNS) diseases, such as septic encephalopathy and stroke. 4,4'-Diaminodiphenylsulfone (DDS, Dapsone) has displayed neuroprotective effect, but whether DDS has protective role on BBB integrity is not clear. This study was designed to examine the effect of DDS on lipopolysaccharide (LPS)-induced BBB disruption and oxidative stress in brain vessels. Using in vivo multiphoton imaging, we found that DDS administration significantly restored BBB integrity compromised by LPS. DDS also increased the expression of tight junction proteins occludin, zona occludens-1 (ZO-1) and claudin-5 in brain vessels. Level of reactive oxygen species (ROS) was reduced by DDS treatment, which may due to decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and NOX2 expression. Our results showed that LPS-induced BBB dysfunction could be attenuated by DDS, indicated that DDS has a therapeutic potential for treating CNS infection and other BBB related diseases.

STIM1 calcium sensor is required for activation of the phagocyte oxidase during inflammation and host defense

The stromal-interacting molecule 1 (STIM1) is a potent sensor of intracellular calcium, which in turn regulates entry of external calcium through plasma membrane channels to affect immune cell activation. Although the contribution of STIM1 to calcium signaling in lymphocytes has been well studied, the role of this protein in neutrophil-mediated inflammation and host defense is unknown. We report that STIM1-deficient murine neutrophils show loss of store-operated calcium entry (SOCE) in response to both soluble ligands that activate G-proteins as well as Fcγ-receptor or integrin ligation that activates tyrosine kinase signaling. This results in modest defects in phagocytosis and degranulation responses but a profound block in superoxide production by the phagocyte oxidase. We trace the primary intracellular target of calcium to be protein kinase C isoforms α and β (PKCα and PKCβ), which in turn phosphorylate subunits of the oxidase leading to superoxide production. In vivo the loss of SOCE in stim1(-/-) chimeric mice results in marked susceptibility to bacterial infections but also protection from tissue injury in hepatic ischemia/reperfusion injury. These results demonstrate the critical role of STIM1-mediated SOCE and define major protein targets of calcium signaling in neutrophil activation during inflammatory disease.

Dapsone in dermatology and beyond

Dapsone (4,4′-diaminodiphenylsulfone) is an aniline derivative belonging to the group of synthetic sulfones. In 1937 against the background of sulfonamide era the microbial activity of dapsone has been discovered. Shortly thereafter, the use of dapsone to treat non-pathogen-caused diseases revealed alternate antiinflammatory mechanisms that initially were elucidated by inflammatory animal models. Thus, dapsone clearly has dual functions of both: antimicrobial/antiprotozoal effects and anti-inflammatory features similarly to non-steroidal anti-inflammatory drugs. The latter capabilities primarily were used in treating chronic inflammatory disorders. Dapsone has been investigated predominantly by in vitro methods aiming to get more insights into the effect of dapsone to inflammatory effector cells, cytokines, and/or mediators, such as cellular toxic oxygen metabolism, myoloperoxidase-/halogenid system, adhesion molecules, chemotaxis, membrane-associated phospholipids, prostaglandins, leukotrienes, interleukin-8, tumor necrosis factor α, lymphocyte functions, and tumor growth. Moreover, attention has been paid to mechanisms by which dapsone mediates effects in more complex settings like impact of lifespan, stroke, glioblastoma, or as anticonvulsive agent. Additionally, there are some dermatological investigations in human being using dapsone and its metabolites (e.g., leukotriene B₄-induced chemotaxis, ultraviolet-induced erythema). It could be established that dapsone metabolites by their own have anti-inflammatory properties. Pharmacology and mechanisms of action are determining factors for clinical use of dapsone chiefly in neutrophilic and/or eosinophilic dermatoses and in chronic disorders outside the field of dermatology. The steroid-sparing effect of dapsone is useful for numerous clinical entities. Future avenues of investigations will provide more information on this fascinating and essential agent.

Antioxidant, anticonvulsive and neuroprotective effects of dapsone and phenobarbital against kainic acid-induced damage in rats

Excitotoxicity due to glutamate receptors (GluRs) overactivation is a leading mechanism of oxidative damage and neuronal death in various diseases. We have shown that dapsone (DDS) was able to reduce both neurotoxicity and seizures associated to the administration of kainic acid (KA), an agonist acting on AMPA/KA receptors (GluK1-GluK5). Recently, it has been shown that phenobarbital (PB) is also able to reduce epileptic activity evoked by that receptor. In the present study, we tested the antioxidative, anticonvulsive and neuroprotective effects of DDS and PB administered alone or in combination upon KA toxicity to rats. Results showed that KA increased lipid peroxidation and diminished reduced glutathione (GSH), 24 h after KA administration and both drugs in combination or individually inhibited these events. Likewise, KA promotes mortality and this event was antagonized by effect of both treatments. Additionally, the behavioral evaluation showed that DDS and PB administered alone or in combination decreased the number of limbic seizures and reduced the percentage of animals showing tonic-clonic seizures versus the control group, which was administered only with KA. Finally, our study demonstrated that all of the treatments prevented the neuronal death of the pyramidal cell layer of hippocampal CA-3. In conclusion, the treatment with DDS and PB administrated alone or in combination exerted antioxidant, anticonvulsive and neuroprotective effects against the neurotoxicity induced by KA in rats, but their effects were not additive. Thus, it may be good options of treatment in diseases such as epilepsy and status epilepicus, administered separately.

Protective effect of 4,4'-diaminodiphenylsulfone against paraquat-induced mouse lung injury

Although 4,4'-diaminodiphenylsulfone (DDS, dapsone) has been used to treat several dermatologic conditions, including Hansen disease, for the past several decades, its mode of action has remained a topic of debate. We recently reported that DDS treatment significantly extends the lifespan of the nematode C. elegans by decreasing the generation of reactive oxygen species. Additionally, in in vitro experiments using non-phagocytic human fibroblasts, we found that DDS effectively counteracted the toxicity of paraquat (PQ). In the present study, we extended our work to test the protective effect of DDS against PQ in vivo using a mouse lung injury model. Oral administration of DDS to mice significantly attenuated the lung tissue damage caused by subsequent administration of PQ. Moreover, DDS reduced the local expression of mRNA transcripts encoding inflammation-related molecules, including endothelin-1 (ET-1), macrophage inflammatory protein-1α (MIP-1α), and transforming growth factor-β (TGF-β). In addition, DDS decreased the PQ-induced expression of NADPH oxidase mRNA and activation of protein kinase Cμ (PKCμ). DDS treatment also decreased the PQ-induced generation of superoxide anions in mouse lung fibroblasts. Taken together, these data suggest the novel efficacy of DDS as an effective protective agent against oxidative stress-induced tissue damages.

Dapsone inhibits IL-8 secretion from human bronchial epithelial cells stimulated with lipopolysaccharide and resolves airway inflammation in the ferret

BACKGROUND

IL-8 is an important activator and chemoattractant for neutrophils that is produced by normal human bronchial epithelial (NHBE) cells through mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) p65 pathways. Dapsone, a synthetic sulfone, is widely used to treat chronic neutrophil dermatoses. We investigated the effects of dapsone on polarized IL-8 secretion from lipopolysaccharide (LPS)-stimulated NHBE cells and further evaluated its ability to decrease LPS-induced inflammation in the ferret airway.

METHODS

NHBE cells were grown at air-liquid interface (ALI) to ciliated differentiation. Baseline and endotoxin (LPS)-stimulated IL-8 secretion was measured by enzyme-linked immunosorbent assay at air and basal sides with and without dapsone. Western blotting was used to determine signaling pathways. In vivo, ferrets were exposed to intratracheal LPS over a period of 5 days. Once inflammation was established, oral or nebulized dapsone was administered for 5 days. Intraepithelial neutrophil accumulation was analyzed histologically, and mucociliary transport was measured on the excised trachea.

RESULTS

Dapsone, 1 μg/mL, did not influence unstimulated (basal) IL-8 secretion. Apical LPS stimulation induced both apical and basolateral IL-8, but basolateral LPS increased only basolateral IL-8. Dapsone inhibited polarized IL-8 secretion from ALI-conditioned cells. Dapsone also decreased LPS-induced IL-8 mRNA level. LPS led to phosphorylation of extracellular signal-regulated kinase 1/2, but not p38 MAPK or c-Jun NH(2)-terminal kinase. LPS also induced NF-κB p65 phosphorylation, an effect that was inhibited by dapsone. Both oral and aerosol dapsone decreased LPS-induced intraepithelial neutrophil accumulation, but only treatment with aerosol dapsone restored mucociliary transport to normal.

CONCLUSIONS

Dapsone, given either systemically or as an aerosol, may be useful in treating neutrophilic airway inflammation.

DDS, 4,4'-diaminodiphenylsulfone, extends organismic lifespan

DDS, 4,4'-diaminodiphenylsulfone, is the most common drug prescribed to treat Hansen disease patients. In addition to its antibacterial activity, DDS has been reported to be involved in other cellular processes that occur in eukaryotic cells. Because DDS treatment significantly enhances the antioxidant activity in humans, we examined its effect on lifespan extension. Here we show that DDS extends organismic lifespan using Caenorhabditis elegans as a model system. DDS treatment caused a delay in aging and decreased the levels of a mitochondrial complex. The oxygen consumption rate was also significantly lowered. Consistent with these data, paraquat treatment evoked less reactive oxygen species in DDS-treated worms, and these worms were less sensitive to paraquat. Interestingly enough, all of the molecular events caused by DDS treatment were consistently reproduced in mice treated with DDS for 3 mo and in the C2C12 muscle cell line. Structural prediction identified pyruvate kinase (PK) as a protein target of DDS. Indeed, DDS bound and inhibited PK in vitro and inhibited it in vivo, and a PK mutation conferred extended lifespan of C. elegans. Supplement of pyruvate to the media protected C2C12 cells from apoptosis caused by paraquat. Our findings establish the significance of DDS in lowering reactive oxygen species generation and extending the lifespan, which renders the rationale to examining the possible effect of DDS on human lifespan extension.

Suppression of ROS generation by 4,4-diaminodiphenylsulfone in non-phagocytic human diploid fibroblasts

The action mode of 4,4-diaminodiphenylsulfone (DDS) is still under debate, although it has long been used in treatment of several dermatologic diseases including Hansens disease. In this study, we tested the effect of DDS as an antioxidant on paraquat-induced oxidative stress in non-phagocytic human diploid fibroblasts (HDFs). Overall, preincubation of HDFs with DDS prevented the oxidative stress and the resulting cytotoxic damages caused by paraquat in these cells. The specific effects of DDS in paraquat-treated HDFs are summarized as follows: a) reducing the expression of NADPH oxidase 4 (NOX4) by inhibiting paraquat-induced activation of PKC; b) inhibiting paraquat-induced decreases in mitochondrial complex protein levels as well as in membrane potentials; c) consequently, inhibiting the generation of cytosolic and mitochondrial superoxide anions. Taken together, these findings suggest that DDS would suppress the radical generation in non-phagocytic HDFs during oxidative stress, and that DDS might have the extended potential to be used further in prevention of other oxidative stress-related pathologies.

Effects of sulphurous water on human neutrophil elastase release

Background: Molecules bearing a sulphide (HS) group, such as glutathione, play a fundamental role in the defensive system of human airways, as shown by the fact that the lining fluid covering the epithelia of the respiratory tract contains very high concentrations of glutathione: the lungs and nose, respectively, contain about 140 and 40 times the concentrations found in plasma. Consequently, various low-weight soluble molecules bearing an HS group (including N-acetylcysteine, mesna and thiopronine, and prodrugs such as stepronine and erdosteine) have been used for therapeutic purposes. HS groups can also be therapeutically administered by means of sulphurous thermal water containing HS groups. The aim of this study was to investigate the direct activity of such water on the release of elastase by activated human neutrophils.

Method: After the neutrophils were incubated with increasing amounts of sulphurous water or the HS/hydrogen sulphide donor sodium hydrosulphide (NaHS), elastase release was initiated by N-formyl-methionyl-leucyl-phenylalanine and measured by means of spectrofluorimetry using methylsuccinylalanylprolylvalyl-methylcoumarin amide as the fluorogenic substrate. To verify the presence of direct action on elastase we determined the diameter of the area of elastinolysis on elastine-agarose gel plates.

Results: The sulphurous water significantly inhibited elastase release at HS concentrations ranging from 4.5 to 18 μg/ml, as assayed using the iodometric method; in the case of NaHS, the inhibition was significant at HS concentrations ranging from 2.2 to 18 μg/ml. The concentration-effect regression lines of both were parallel and neither showed any direct elastolytic activity.

Conclusions: Previous claims concerning the activity of sulphurous water have been based on the patients’ subjective sense of wellbeing and on symptomatic (or general) clinical improvements that are not easy to define or quantify exactly. Our findings indicate that, in addition to its known mucolytic and antioxidant activity, sulphurous water also has an anti-elastase activity that may help to control the inflammatory processes of upper and lower airway diseases.

Efficacy of dapsone in the treatment of pemphigus and pemphigoid: analysis of current data

Dapsone is a chemotherapeutic agent primarily used in treating leprosy, Pneumocystis jiroveci (previously carinii) pneumonia, and malaria. It is also used as an adjuvant in the treatment of pemphigus and pemphigoid. To assess the role of dapsone in the treatment of pemphigus and pemphigoid, a retrospective review of reports in the English-language literature was conducted. Information on the number of patients treated, their average age, prior therapies, indications for use, protocol (dose and interval) used, concomitant therapies, reported adverse effects, and clinical outcomes were analyzed. There were 35 case reports/series published describing the use of dapsone in a total of 427 patients. Data on 55 pemphigus patients were obtained from several case reports and some case series and one randomized controlled trial. Of these, 32 patients with pemphigus vulgaris and 14 patients with pemphigus foliaceus responded to dapsone. Data from 13 case series, each including at least five patients, accounted for 372 patients with pemphigoid. The overall response rates to dapsone, when given either alone or in combination with corticosteroids or immunosuppressive agents, were 84% in mucous membrane pemphigoid, and 81% in bullous pemphigoid. Hemolysis was the most common adverse effect observed. Dapsone is a promising and useful agent in patients with autoimmune mucocutaneous blistering diseases, especially in mucous membrane pemphigoid. It can be used as a corticosteroid-sparing agent. Therefore, its combined use with oral corticosteroids may be useful in pemphigus vulgaris and bullous pemphigoid. Adverse effects of dapsone are dose dependent and usually reversible. Hemolysis and concomitant anemia secondary to hemolysis are expected in most patients. In the opinion of the authors, dapsone is underutilized in the treatment of autoimmune mucocutaneous blistering diseases.

Myristic Acid, A Side Chain of Phorbol Myristate Acetate (PMA), Can Activate Human Polymorphonuclear Leukocytes to Produce Oxygen Radicals More Potently than PMA

Myristic acid (MyA), which is a saturated fatty acid (C14:0) and a side chain of phorbol 12-myristate 13-acetate (PMA), was examined if MyA stimulates human polymorphonuclear leukocytes (PMNs) to release oxygen radicals comparable to PMA by applying electron paramagnetic resonance (EPR)-spin-trapping method. When MyA was added to isolated human PMNs, spin adducts of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OH and DMPO-OOH were time-dependently observed. The amounts of these spin adducts were larger than those of PMNs stimulated by PMA. These results clearly show that MyA is more potent agent to prime human PMNs than PMA, in a point of view of not only O₂^·− but also ·OH production. This fact calls attention that too much intake of MyA that is known to be contained vegetable oils can lead to crippling effect through uncontrolled production of reactive oxygen species.

Antioxidant, antiinflammatory and antiapoptotic effects of dapsone in a model of brain ischemia/reperfusion in rats

Although dapsone (4,4'-diaminodiphenylsulfone) has been described as a neuroprotective agent in occlusive focal ischemia in rats, its mechanism of action is still unknown. To explore this mechanism, oxidative, inflammatory and apoptotic processes were evaluated in the striatum of adult rats using a model of ischemia-reperfusion (I/R), either with or without dapsone treatment. Male Wistar rats were submitted to transient middle cerebral artery occlusion for 2 hr, followed by reperfusion. Rats were dosed either with dapsone (12.5 mg/kg i.p.) or vehicle 30 min before or 30 min after the ischemia onset. Lipid peroxidation (LP) and nitrotyrosine contents were measured 22 hr after reperfusion, and myeloperoxidase activity was evaluated 46 hr after I/R. Different markers for apoptosis and necrosis were also evaluated both at 24 and 72 hr after I/R experimental procedure. LP increased by 37% in ischemic animals vs controls, and this effect was reversed by dapsone treatments. A similar effect was observed regarding nitrotyrosine striatal contents. Myeloperoxidase activity, a marker of inflammatory response, increased 3.7-fold in ischemic animals vs. control rats, and dapsone treatment antagonized that effect. Although apoptosis was increased by the effect of ischemia at both evaluation times, dapsone antagonized that effect only at 72 hr after surgery. Dapsone antagonized all of the I/R end points measured, showing a remarkable ability to decrease markers of damage through antioxidant, antiinflammatory, and anti-apoptotic effects.

Sweet's syndrome in association with common variable immunodeficiency

Sweet's syndrome (SS), a rare reactive neutrophilic dermatosis, has been reported to occur in association with a variety of systemic disorders, categorized by von den Diesch into idiopathic, paraneoplastic, pregnancy and parainflammatory subgroups. The parainflammatory group has been well defined, and includes a wide spectrum of infectious triggers and disorders of immune dysregulation. To date, however, no cases of SS have been described in the context of common variable immunodeficiency (CVID). We report a case of paediatric-onset SS, previously reported as idiopathic, with a subsequent diagnosis of CVID.

Galectin-3 but not galectin-1 induces mast cell death by oxidative stress and mitochondrial permeability transition

Galectin-1 and galectin-3 are the most ubiquitously expressed members of the galectin family and more importantly, these two molecules are shown to have opposite effects on pro-inflammatory responses and/or apoptosis depending on the cell type. Herein, we demonstrate for the first time that galectin-3 induces mast cell apoptosis. Mast cells expressed substantial levels of galectin-3 and galectin-1 and to a lesser extent the receptor for advanced glycation end products (RAGE) on their surfaces. Treatment of cells with galectin-3 at concentrations of > or =100 nM for 18-44 h resulted in cell death by apoptosis. Galectin-3-induced apoptosis was completely prevented by lactose, neutralizing antibody to RAGE, and the caspase-3 inhibitor z-DEVD-fmk. Galectin-3-induced apoptosis was also completely abolished by dithiothreitol and superoxide dismutase, but not inhibited by catalase. Moreover, galectin-3 but not galectin-1 induced the release of superoxide, which was blocked by lactose, anti-RAGE, and dithiothreitol. Finally, galectin-3-induced apoptosis was blocked by bongkrekic acid, an antagonist of the mitochondrial permeability transition pore (PTP), while atractyloside, an agonist of the PTP, greatly facilitated galectin-1-induced apoptosis. These data suggest that galectin-3 induces oxidative stress, PTP opening, and the caspase-dependent death pathway by binding to putative surface receptors including RAGE via the carbohydrate recognition domain.