Treatment of Sulfur Mustard Corneal Injury by Augmenting the DNA Damage Response (DDR): A Novel Approach.

Sulfur mustard (SM) is a highly reactive organic chemical has been used as a chemical warfare agent and terrorist threat since World War I. The cornea is highly sensitive to SM toxicity and exposure to low vapor doses can cause incapacitating acute injuries. Exposure to higher doses can elicit persistent secondary keratopathies that cause reduced quality of life and impaired or lost vision. Despite a century of research, there are no specific treatments for acute or persistent ocular SM injuries. SM cytotoxicity emerges, in part, through DNA alkylation and double-strand breaks (DSBs). Because DSBs can naturally be repaired by DNA damage response pathways with low efficiency, we hypothesized that enhancing the homologous recombination pathway could pose a novel approach to mitigate SM injury. Here, we demonstrate that a dilithium salt of adenosine diphosphoribose (INV-102) increases protein levels of p53 and Sirtuin 6, upregulates transcription of BRCA1/2, enhances γH2AX focus formation, and promotes assembly of repair complexes at DSBs. Based on in vitro evidence showing INV-102 enhancement of DNA damage response through both p53-dependent and p53-independent pathways, we next tested INV-102 in a rabbit preclinical model of corneal injury. In vivo studies demonstrate a marked reduction in the incidence and severity of secondary keratopathies in INV-102-treated eyes compared with vehicle-treated eyes when treatment was started 24 hours after SM vapor exposure. These results suggest DNA repair mechanisms are a viable therapeutic target for SM injury and suggest topical treatment with INV-102 is a promising approach for SM as well as other conditions associated with DSBs. SIGNIFICANCE STATEMENT: Sulfur mustard gas corneal injury currently has no therapeutic treatment. This study aims to show the therapeutic potential of activating the body's natural DNA damage response to activate tissue repair.

Role of Hypoxia Inducible Factor-1α (HIF-1α) in Innate Defense against Uropathogenic Escherichia coli Infection.

Uropathogenic E. coli (UPEC) is the primary cause of urinary tract infections (UTI) affecting approximately 150 million people worldwide. Here, we revealed the importance of transcriptional regulator hypoxia-inducible factor-1 α subunit (HIF-1α) in innate defense against UPEC-mediated UTI. The effects of AKB-4924, a HIF-1α stabilizing agent, were studied using human uroepithelial cells (5637) and a murine UTI model. UPEC adherence and invasion were significantly reduced in 5637 cells when HIF-1α protein was allowed to accumulate. Uroepithelial cells treated with AKB-4924 also experienced reduced cell death and exfoliation upon UPEC challenge. In vivo, fewer UPEC were recovered from the urine, bladders and kidneys of mice treated transurethrally with AKB-4924, whereas increased bacteria were recovered from bladders of mice with a HIF-1α deletion. Bladders and kidneys of AKB-4924 treated mice developed less inflammation as evidenced by decreased pro-inflammatory cytokine release and neutrophil activity. AKB-4924 impairs infection in uroepithelial cells and bladders, and could be correlated with enhanced production of nitric oxide and antimicrobial peptides cathelicidin and ß-defensin-2. We conclude that HIF-1α transcriptional regulation plays a key role in defense of the urinary tract against UPEC infection, and that pharmacological HIF-1α boosting could be explored further as an adjunctive therapy strategy for serious or recurrent UTI.

Oral delivery of prolyl hydroxylase inhibitor: AKB-4924 promotes localized mucosal healing in a mouse model of colitis.

BACKGROUND: Pharmacological induction of hypoxia-inducible factor (HIF), a global transcriptional regulator of the hypoxic response, by prolyl hydroxylase inhibitors (PHDi) is protective in murine models of colitis, and epithelial cells are critical for the observed therapeutic efficacy. Because systemic HIF activation may lead to potentially negative off-target effects, we hypothesized that targeting epithelial HIF through oral delivery of PHDi would be sufficient to protect against colitis in a mouse model. METHODS: Using a chemically induced trinitrobenzene sulfonic acid murine model of colitis, we compared the efficacy of oral and intraperitoneal (i.p.) delivery of the PHDi; AKB-4924 in preventing colitis, as measured by endoscopy, histology, barrier integrity, and immune profiling. Furthermore, we measured potential off-target effects, examining HIF and HIF target genes in the heart and kidney, as well as erythropoietin and hematocrit levels. RESULTS: Oral administration of AKB-4924 exhibited mucosal protection comparable i.p. dosing. Oral delivery of PHDi led to reduced colonic epithelial HIF stabilization compared with i.p. delivery, but this was still sufficient to induce transcription of downstream HIF targets. Furthermore, oral delivery of PHDi led to reduced stabilization of HIF and activation of HIF targets in extraintestinal organs. CONCLUSIONS: Oral delivery of PHDi therapies to this intestinal mucosa protects against colitis in animal models and represents a potential therapeutic strategy for inflammatory bowel disease, which also precludes unwanted extraintestinal effects.

A new pharmacological agent (AKB-4924) stabilizes hypoxia inducible factor-1 (HIF-1) and increases skin innate defenses against bacterial infection.

Hypoxia inducible factor-1 (HIF-1) is a transcription factor that is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. HIF-1 is also activated in response to bacterial pathogens and supports the innate immune response of both phagocytes and keratinocytes. In this work, we show that a new pharmacological compound AKB-4924 increases HIF-1 levels and enhances the antibacterial activity of phagocytes and keratinocytes against both methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus in vitro. AKB-4924 is also effective in stimulating the killing capacity of keratinocytes against the important opportunistic skin pathogens Pseudomonas aeruginosa and Acinetobacter baumanii. The effect of AKB-4924 is mediated through the activity of host cells, as the compound exerts no direct antimicrobial activity. Administered locally as a single agent, AKB-4924 limits S. aureus proliferation and lesion formation in a mouse skin abscess model. This approach to pharmacologically boost the innate immune response via HIF-1 stabilization may serve as a useful adjunctive treatment for antibiotic-resistant bacterial infections.

A randomized, double-blind, placebo-controlled trial on intravenous ibuprofen L-lysine for the early closure of nonsymptomatic patent ductus arteriosus within 72 hours of birth in extremely low-birth-weight infants.

A multicenter, double-blind, randomized, placebo-controlled trial was conducted to evaluate the efficacy and safety of intravenous (IV) ibuprofen (L-lysine) for the early closure of nonsymptomatic patent ductus arteriosus (PDA) within 72 hours of birth in extremely low-birth-weight (ELBW) infants with evidence of ductal shunting by echocardiogram. Eleven sites enrolled 136 infants with nonsymptomatic early PDA (gestational age < 30 weeks; body weight 500 to 1000 g) to receive a 3-day course (10 mg/kg, 5 mg/kg, and 5 mg/kg) of IV ibuprofen ( N = 68) or placebo ( N = 68). Cardiac echocardiogram was performed on study days 1 and 14, and with rescue. Infants were followed to 36 weeks postconceptional age. Patient demographics, mean (standard deviation), were similar between ibuprofen and placebo: birth weight: 798.5 g (128.7) versus 797.3 g (132.8); gestational age: 26.1 weeks (1.3) versus 26.2 weeks (1.4); and age at first dose: 1.5 days (0.7). The intent-to-treat analysis of the primary endpoint, subjects rescued, died, or dropped through study day 14, was 21/68 (30.9%) with ibuprofen and 36/68 (52.9%) for placebo ( P = 0.005). Death, intraventricular hemorrhage, necrotizing enterocolitis, daily fluid intake/output, liver function, bronchopulmonary dysplasia, and retinopathy of prematurity did not differ. A trend toward decreased periventricular leukomalacia by ibuprofen was noted. IV ibuprofen was effective and safe in the early closure of PDA in preterm neonates.

Efficacy and tolerability of adding prescription omega-3 fatty acids 4 g/d to simvastatin 40 mg/d in hypertriglyceridemic patients: an 8-week, randomized, double-blind, placebo-controlled study.

BACKGROUND: Patients with elevated serum triglyceride (TG) levels often have elevations in non-high-density lipoprotein cholesterol (non-HDL-C) levels as well. The National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) has identified non-HDL-C as a secondary therapeutic target in these patients, but treatment goals may not be reached with statin monotherapy alone. OBJECTIVE: This study evaluated the effects on non-HDL-C and other variables of adding prescription omega-3-acid ethyl esters (P-OM3; Lovaza, formerly Omacor [Reliant Pharmaceuticals, Inc., Liberty Corner, New Jersey]) to stable statin therapy in patients with persistent hypertriglyceridemia. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled, parallel-group study in adults who had received > or = 8 weeks of stable statin therapy and had mean fasting TG levels > or = 200 and < 500 mg/dL and mean low-density lipoprotein cholesterol levels < or = 10% above their NCEP ATP III goal. The study regimen consisted of an initial 8 weeks of open-label simvastatin 40 mg/d and dietary counseling, followed by 8 weeks of randomized treatment with double-blind P-OM3 4 g/d plus simvastatin 40 mg/d or placebo plus simvastatin 40 mg/d. The main outcome measure was the percent change in non-HDL-C from baseline to the end of treatment. RESULTS: The evaluable population included 254 patients, of whom 57.5% (146) were male and 95.7% (243) were white. The mean (SD) age of the population was 59.8 (10.4) years, and the mean weight was 92.0 (19.6) kg. At the end of treatment, the median percent change in non-HDL-C was significantly greater with P-OM3 plus simvastatin compared with placebo plus simvastatin (-9.0% vs -2.2%, respectively; P < 0.001). P-OM3 plus simvastatin was associated with significant reductions in TG (29.5% vs 6.3%) and very-low-density lipoprotein cholesterol (27.5% vs 7.2%), a significant increase in high-density lipoprotein cholesterol (HDL-C) (3.4% vs -1.2%), and a significant reduction in the total cholesterol:HDL-C ratio (9.6% vs 0.7%) (all, P < 0.001 vs placebo). Adverse events (AEs) reported by > or= 1% of patients in the P-OM3 group that occurred with a higher frequency than in the group that received simvastatin alone were nasopharyngitis (4 [3.3%]), upper respiratory tract infection (4 [3.3%]), diarrhea (3 [2.5%]), and dyspepsia (3 [2.5%]). There was no significant difference in the frequency of AEs between groups. No serious AEs were considered treatment related. CONCLUSION: In these adult, mainly white patients with persistent hypertriglyceridemia, P-OM3 plus simvastatin and dietary counseling improved non-HDL-C and other lipid and lipoprotein parameters to a greater extent than simvastatin alone.

Cytoprotective agent in Lactobacillus bulgaricus extracts.

Adenosine 5'-diphosphoribose (ADP-ribose) has been identified as a significant contributor to the anti-cytotoxic activity of Lactobacillus bulgaricus extracts. Although the biological activities associated with the administration of probiotic bacteria and components thereof are sometimes attributed to the peptidoglycans that comprise a substantial portion of the Gram-positive bacterial cell wall, we found that the beta-nicotine adenine dinucleotide (NAD) hydrolysis product ADP-ribose was a significant contributor to the observed anti-cytotoxicity in our L. bulgaricus extracts. The ADP-ribose was isolated, identified, and quantitated by high performance liquid chromatography (HPLC) and by nuclear magnetic resonance (NMR) spectroscopy. ADP-ribose levels as low as 5 mg/L exhibited a measurable inhibition of tumor necrosis factor alpha (TNF-alpha) mediated cytotoxicity in an in vitro cell assay, whereas the ADP-ribose content of the L. bulgaricus extracts often exceeded 5 mg/g dry weight.

Health effects of ultraviolet irradiation in asthmatic children's homes.

OBJECTIVE: Centrally installed ultraviolet (UV) irradiation units were investigated to determine the potential health benefits in mold-sensitized asthmatic children. METHODS: Nineteen mold-sensitized asthmatic children 5 to 17 years of age with home central ventilation systems were enrolled in a 28-week double-blinded placebo controlled cross-over trial. Clinical outcome measurements included morning and evening peak expiratory flow rates (PEFR), PEFR variability, change in forced expiratory volume in 1 second (FEV1), change in total rhinoconjunctivitis and asthma symptom scores, change in rhinoconjunctivitis and asthma quality-of-life scores, and total (rescue and controller) medication use from baseline and between time periods. Environmental outcomes included changes in temperature, relative humidity, dew point, and indoor airborne mold and bacterial counts from baseline and between time periods. Analysis of variance (ANOVA) and regression analysis and t test were used to evaluate relationships between environmental exposure(s) and clinical outcome measurements during each study period. RESULTS: Twelve male and seven female children, average age 10.6 years, were enrolled. A statistically significant improvement in PEFR variability in subjects receiving CREON2000 units followed by placebo units was observed (p < 0.05) across both treatment periods. Within group analysis during treatment period 1, a statistically significant improvement in reduction of asthma symptom scores, the number of days with asthma symptoms, total asthma medication use, and PEFR variability were observed in subjects receiving CREON2000 units versus placebo units (p < 0.05). No significant differences were observed between the CREON 2000 and placebo units for other clinical or environmental outcome measurements. CONCLUSIONS: Central UV irradiation was effective at reducing airway hyperresponsiveness manifested as PEFR variability and some clinical symptoms. A larger cohort controlled longitudinal study to validate the clinical health effects of UV irradiation as a primary indoor environmental intervention for allergic asthma is necessary to confirm this finding.

Effects of fenofibrate on atherogenic dyslipidemia in hypertriglyceridemic subjects.

BACKGROUND: The metabolic syndrome (MS) is often accompanied by atherogenic dyslipidemia, which is characterized by elevated triglycerides (TG), reduced high-density lipoprotein cholesterol (HDL-C), and elevated numbers of small, dense low-density lipoprotein (LDL) particles. HYPOTHESIS: It was hypothesized that a threshold exists for the circulating TG level needed to produce changes in LDL subclass distribution. METHODS: Hypertriglyceridemic (TG > or =300 and <1000 mg/dl) subjects with the MS were randomly assigned to placebo (n=50) or 130 mg/day of micronized fenofibrate-coated microgranules (n=96) for 8 weeks. RESULTS: In the overall analysis, fenofibrate treatment resulted in significant (p < 0.05) changes versus placebo in TG (-36.6%), non-HDL-C (-7.5%), very low-density lipoprotein-C (-32.7%), LDL-C (15.0%), HDL-C (14.0%), remnant lipoprotein-C (-35.1%), apolipoprotein B (-6.0%), apolipoprotein A-I (5.3%), and apolipoprotein C-III--29.7%). Changes in LDL particle diameter in the fenofibrate group were significantly inversely associated with the TG level achieved on treatment (p = 0.019). When individually matched for percent change in TG, subjects with on-treatment TG < 200 mg/dl, in contrast to those with on-treatment values > or =200 mg/dl, had significantly different median responses (p < 0.05) in LDL size (0.79 vs. -0.06 nm) and cholesterol carried by small (-35 vs. 21 mg/dl) and large (31 vs. 11 mg/dl) particles. CONCLUSION: These data support the view that a threshold exists below which the TG level must be lowered to produce shifts in LDL particle size.