VBP15, a glucocorticoid analogue, is effective at reducing allergic lung inflammation in mice

Asthma is a chronic inflammatory condition of the lower respiratory tract associated with airway hyperreactivity and mucus obstruction in which a majority of cases are due to an allergic response to environmental allergens. Glucocorticoids such as prednisone have been standard treatment for many inflammatory diseases for the past 60 years. However, despite their effectiveness, long-term treatment is often limited by adverse side effects believed to be caused by glucocorticoid receptor-mediated gene transcription. This has led to the pursuit of compounds that retain the anti-inflammatory properties yet lack the adverse side effects associated with traditional glucocorticoids. We have developed a novel series of steroidal analogues (VBP compounds) that have been previously shown to maintain anti-inflammatory properties such as NFκB-inhibition without inducing glucocorticoid receptor-mediated gene transcription. This study was undertaken to determine the effectiveness of the lead compound, VBP15, in a mouse model of allergic lung inflammation. We show that VBP15 is as effective as the traditional glucocorticoid, prednisolone, at reducing three major hallmarks of lung inflammation--NFκB activity, leukocyte degranulation, and pro-inflammatory cytokine release from human bronchial epithelial cells obtained from patients with asthma. Moreover, we found that VBP15 is capable of reducing inflammation of the lung in vivo to an extent similar to that of prednisone. We found that prednisolone--but not VBP15 shortens the tibia in mice upon a 5 week treatment regimen suggesting effective dissociation of side effects from efficacy. These findings suggest that VBP15 may represent a potent and safer alternative to traditional glucocorticoids in the treatment of asthma and other inflammatory diseases.Supported in part by grants from the NIH (1R41HL104939-01B; 1K26RR032082; 1P50AR060836-01; 1U54HD071601; 2R24HD050846-06, R01 HL033152- 25), DOD grants (W81XWH-11-1-0330; W81XWH-11-1-0782; W81XWH-10-1-0659; W81XWH-11-1-0809; W81XWH-09-1-0599) a translational research grant from MDA, pilot grant from Parent Project Muscular Dystrophy (PPMD), and a contribution from the Clark Family Foundation

Widespread Occurrence of Phage-encoded Exotoxin Genes in Terrestrial and Aquatic Environments in Southern California

Many human diseases are caused by pathogens that produce exotoxins. The genes that encode these exotoxins are frequently encoded by mobile DNA elements such as plasmids or phage. Mobile DNA elements can move exotoxin genes among microbial hosts, converting avirulent bacteria into pathogens. Phage and bacteria from water, soil, and sediment environments represent a potential reservoir of phage- and plasmid-encoded exotoxin genes. The genes encoding exotoxins that are the causes of cholera, diphtheria, enterohemorrhagic diarrhea, and Staphylococcus aureus food poisoning were found in soil, sediment, and water samples by standard PCR assays from locations where the human diseases are uncommon or nonexistent. On average, at least one of the target exotoxin genes was detected in ∼15% of the more than 300 environmental samples tested. The results of standard PCR assays were confirmed by quantitative PCR (QPCR) and Southern dot blot analyses. Agreement between the results of the standard PCR and QPCR ranged from 63% to 84%; and the agreement between standard PCR and Southern dot blots ranged from 50% to 66%. Both the cholera and shiga exotoxin genes were also found in the free phage DNA fraction. The results indicate that phage-encoded exotoxin genes are widespread and mobile in terrestrial and aquatic environments

VBP15, a glucocorticoid analogue, is effective at reducing allergic Lung inflammation in mice

Asthma is a chronic inflammatory condition of the lower respiratory tract associated with airway hyperreactivity and mucus obstruction in which a majority of cases are due to an allergic response to environmental allergens. Glucocorticoids such as prednisone have been standard treatment for many inflammatory diseases for the past 60 years. However, despite their effectiveness, long-term treatment is often limited by adverse side effects believed to be caused by glucocorticoid receptor-mediated gene transcription. This has led to the pursuit of compounds that retain the anti-inflammatory properties yet lack the adverse side effects associated with traditional glucocorticoids. We have developed a novel series of steroidal analogues (VBP compounds) that have been previously shown to maintain anti-inflammatory properties such as NFκB-inhibition without inducing glucocorticoid receptor-mediated gene transcription. This study was undertaken to determine the effectiveness of the lead compound, VBP15, in a mouse model of allergic lung inflammation. We show that VBP15 is as effective as the traditional glucocorticoid, prednisolone, at reducing three major hallmarks of lung inflammation—NFκB activity, leukocyte degranulation, and pro-inflammatory cytokine release from human bronchial epithelial cells obtained from patients with asthma. Moreover, we found that VBP15 is capable of reducing inflammation of the lung in vivo to an extent similar to that of prednisone. We found that prednisolone–but not VBP15 shortens the tibia in mice upon a 5 week treatment regimen suggesting effective dissociation of side effects from efficacy. These findings suggest that VBP15 may represent a potent and safer alternative to traditional glucocorticoids in the treatment of asthma and other inflammatory diseases

VBP15, a Glucocorticoid Analogue, Is Effective at Reducing Allergic Lung Inflammation in Mice

Asthma is a chronic inflammatory condition of the lower respiratory tract associated with airway hyperreactivity and mucus obstruction in which a majority of cases are due to an allergic response to environmental allergens. Glucocorticoids such as prednisone have been standard treatment for many inflammatory diseases for the past 60 years. However, despite their effectiveness, long-term treatment is often limited by adverse side effects believed to be caused by glucocorticoid receptor-mediated gene transcription. This has led to the pursuit of compounds that retain the anti-inflammatory properties yet lack the adverse side effects associated with traditional glucocorticoids. We have developed a novel series of steroidal analogues (VBP compounds) that have been previously shown to maintain anti-inflammatory properties such as NFκB-inhibition without inducing glucocorticoid receptor-mediated gene transcription. This study was undertaken to determine the effectiveness of the lead compound, VBP15, in a mouse model of allergic lung inflammation. We show that VBP15 is as effective as the traditional glucocorticoid, prednisolone, at reducing three major hallmarks of lung inflammation-NFκB activity, leukocyte degranulation, and pro-inflammatory cytokine release from human bronchial epithelial cells obtained from patients with asthma. Moreover, we found that VBP15 is capable of reducing inflammation of the lung in vivo to an extent similar to that of prednisone. We found that prednisolone-but not VBP15 shortens the tibia in mice upon a 5 week treatment regimen suggesting effective dissociation of side effects from efficacy. These findings suggest that VBP15 may represent a potent and safer alternative to traditional glucocorticoids in the treatment of asthma and other inflammatory diseases

VBP15 reduces acute allergic lung inflammation.

<p>OVA-challenged mice were either left untreated or treated with oral doses of prednisone, VBP15 (20 mg/kg), or cherry syrup alone daily for 6 days. A group of non-challenged mice (naïve) was included in order to assess basal inflammatory parameters. Perfused whole lungs were processed for histological analysis and stained with H&E (A) or PAS (B). Images (10× magnification) represent areas of tissue surrounding bronchioles. Arrows on H&E sections indicate inflammatory foci. Percentage of PAS positive airways were counted via bright field microscopy (C). Bar graph represents mean (±SE)% PAS positive airways. *<i>p</i><.05; **<i>p</i><0.01 compared to the vehicle control group with n = 5 mice per group. IL-13 (D) and RANTES (E) were measured in BAL fluid by flow cytometric bead array. Bar graphs represent mean (±SE) cytokine concentration values. *<i>p</i><.05; **<i>p</i><0.01 compared to syrup group with n = 5 mice per group.</p

VBP15 reduces leukocyte degranulation.

<p>Anti-DNP-sensitized RBL-2H3 cells were treated with prednisolone (50 µM), VBP-15 (50 µM), or vehicle control (DMSO) for 7 minutes followed by addition of DNP to induce degranulation. The reaction was allowed to proceed for an additional 20 minutes before supernatant was removed and tested for β-hexosaminidase content. A well of untreated cells was lysed to gauge total β-hexosamindase content. Release percentage was determined using a formula described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063871#s2" target="_blank">Materials and Methods</a>. Bar graph represents mean (±SE) release percentage. **p<0.01 compared to vehicle control. Data represents 3 biological replicates with assay performed in triplicate. N.S. = Not statistically significant.</p

VBP15 inhibits NFκB activity.

<p>A549 cells stably-transfected with a luciferase NFκB construct were exposed to increasing concentrations of VBP15 or prednisolone (3, 30, 300, 3000 nM) followed by TNFα stimulation before measuring luciferase activity. Bar graph represents mean (±SE) luciferase units. *<i>p</i><.012 (due to the Bonferroni adjustment for multiple comparisons) compared to treatment with vehicle control. Data represents 4 biological replicates with assay performed in triplicate.</p

VBP15 does not induce tibia length shortening.

<p>Wildtype outbred CD1 mice were treated daily for 5 weeks with VBP15 (30 and 45 mg/kg), prednisolone (10 mg/kg) or vehicle control starting at 12 days of age. At the end of the treatment, tibias were harvested and measured. Bar graph represents mean (±SE) tibia length values. *p<0.05 compared to vehicle control with n = 10 mice/group.</p

VBP15 reduces basolateral cytokine secretion from human bronchial epithelial cells obtained from asthmatic patients.

<p>HBE cells from 3 separate human donors were pulse-treated with VBP15 (10 µM) or vehicle control (DMSO). Basolateral surface supernatant was tested for the presence of TGFβ1 (left panel) and IL-13 (right panel) by flow cytometric bead array. Bar graphs represent mean (±SE) concentration values. **, <i>p</i><0.01 compared to vehicle control with n = 3 donors. N.D. = Not Detectible (lower limit of detection = 4.5 pg/ml).</p