Remodeling oncogenic transcriptomes by small molecules targeting NONO

Much of the human proteome is involved in mRNA homeostasis, but most RNA-binding proteins lack chemical probes. Here we identify electrophilic small molecules that rapidly and stereoselectively decrease the expression of transcripts encoding the androgen receptor and its splice variants in prostate cancer cells. We show by chemical proteomics that the compounds engage C145 of the RNA-binding protein NONO. Broader profiling revealed that covalent NONO ligands suppress an array of cancer-relevant genes and impair cancer cell proliferation. Surprisingly, these effects were not observed in cells genetically disrupted for NONO, which were instead resistant to NONO ligands. Reintroduction of wild-type NONO, but not a C145S mutant, restored ligand sensitivity in NONO-disrupted cells. The ligands promoted NONO accumulation in nuclear foci and stabilized NONO-RNA interactions, supporting a trapping mechanism that may prevent compensatory action of paralog proteins PSPC1 and SFPQ. These findings show that NONO can be co-opted by covalent small molecules to suppress protumorigenic transcriptional networks.

Proteomic discovery of chemical probes that perturb protein complexes in human cells

Most human proteins lack chemical probes, and several large-scale and generalizable small-molecule binding assays have been introduced to address this problem. How compounds discovered in such "binding-first" assays affect protein function, nonetheless, often remains unclear. Here, we describe a "function-first" proteomic strategy that uses size exclusion chromatography (SEC) to assess the global impact of electrophilic compounds on protein complexes in human cells. Integrating the SEC data with cysteine-directed activity-based protein profiling identifies changes in protein-protein interactions that are caused by site-specific liganding events, including the stereoselective engagement of cysteines in PSME1 and SF3B1 that disrupt the PA28 proteasome regulatory complex and stabilize a dynamic state of the spliceosome, respectively. Our findings thus show how multidimensional proteomic analysis of focused libraries of electrophilic compounds can expedite the discovery of chemical probes with site-specific functional effects on protein complexes in human cells.

Discovery of an Allosteric, Inactive Conformation-Selective Inhibitor of Full-Length HPK1 Utilizing a Kinase Cascade Assay

Achieving selectivity across the human kinome is a major hurdle in kinase inhibitor drug discovery. Assays using active, phosphorylated protein kinases bias hits toward poorly selective inhibitors that bind within the highly conserved adenosine triphosphate (ATP) pocket. Targeting inactive (vs active) kinase conformations offers advantages in achieving selectivity because of their more diversified structures. Kinase cascade assays are typically initiated with target kinases in their unphosphorylated inactive forms, which are activated during the assays. Therefore, these assays are capable of identifying inhibitors that preferentially bind to the unphosphorylated form of the enzyme in addition to those that bind to the active form. We applied this cascade assay to the emerging cancer immunotherapy target hematopoietic progenitor kinase 1 (HPK1), a serine/threonine kinase that negatively regulates T cell receptor signaling. Using this approach, we discovered an allosteric, inactive conformation-selective triazolopyrimidinone HPK1 inhibitor, compound 1. Compound 1 binds to unphosphorylated HPK1 >24-fold more potently than active HPK1, is not competitive with ATP, and is highly selective against kinases critical for T cell signaling. Furthermore, compound 1 does not bind to the isolated HPK1 kinase domain alone but requires other domains. Together, these data indicate that 1 is an allosteric HPK1 inhibitor that attenuates kinase autophosphorylation by binding to a pocket consisting of residues within and outside of the kinase domain. Our study demonstrates that cascade assays can lead to the discovery of highly selective kinase inhibitors. The triazolopyrimidinone described in this study may represent a privileged chemical scaffold for further development of potent and selective HPK1 inhibitors.

1602 A Quality Improvement Project on The Management of Patients with Traumatic Head Injury Presenting to A District General Hospital

Introduction

Traumatic Brain Injury (TBI) is associated with morbidity and mortality. All District General Hospitals (DGH) in West Midlands liaise with Neurosurgery centres for management of these patients through a referral system (NORSe). The aim of this study was to assess outcomes in TBI following the implementation of vital interventions.

Method

A retrospective data was collected between 1/1/2019 and 1/12/2020. We included all patients admitted with traumatic brain injury over the age of 16. We accessed the data from the hospital database, clinical notes, and NORSe. A re-audit was performed following implementations of recommendations (proforma and care of elderly input). Further data were collected prospectively.

Results

Our cohort included n1=61 patients (first cycle) and n2= 29 (second cycle). The demographic age and gender were comparable in both cycles. The median time for Neurosurgery advice was 229 minutes (IQR 60-690) in the first cycle as compared to 80 minutes (IQR 40-120, P < 0.05) and the main cause for delay was inadequate information transfer. The mortality rate was 24% (5 were attributed to sepsis), as compared to 14% in the second cycle. The median length of stay (LOS) was 4 days (IQR 3-13.5) in the first cycle, which translates to a cost of £26,815 per quarter. In comparison, LOS was 3 days (IQR 2-4), which translates to the cost of bed occupancy of £12,771 and saving of £14,043 per quarter, in the second cycle.

Conclusions

The introduction of simple interventions in a DGH can help to significantly improve patient outcomes in those admitted with Traumatic brain injury.

Potent Phenylpyridine and Oxodihydrofuran Inhibitors of Cyclooxygenase-2: Optimization toward a Long Residence Time with Balanced Internal Energetics

Long residence time enzyme inhibitors with a two-step binding mechanism are characterized by a high internal energy barrier for target association. This raises the question of whether optimizing residence time via further increasing this internal energy barrier would inevitably lead to insufficient target occupancy in vivo due to slow, time-dependent binding. We attempted to address this question during optimization of cyclooxygenase-2 (COX-2) inhibitors. Defining long residence time drugs with acceptable association and dissociation rate constants required for sufficient target occupancy and sustained efficacy, which we termed "balanced internal energetics", provides an important criterion for successful progression during lead optimization. Despite the advancement of several COX-2 inhibitors to marketed drugs, their detailed inhibition kinetics have been surprisingly limiting especially during the structure-activity relationship process mainly due to the lack of robust kinetic assays. Herein, we describe a reoptimized COX enzymatic assay and a novel MS-based assay enabling detailed mechanistic studies for identifying long residence time COX-2 inhibitors with balanced internal energetics. These efforts led to the discovery of promising leads possessing dissociation half-lives of ≤40 h, much greater than the values of 6 and 0.71 h for two marketed drugs, etoricoxib and celecoxib, respectively. Importantly, the inhibition rate constants remain comparable to those of the marketed drugs and above the lower limits set by the criteria of balanced internal energetics, predicting sufficient target occupancy required for efficacy. Taken together, this study demonstrates the feasibility of increasing the internal energy barrier as a viable approach for lead optimization toward discovering long residence time drug candidates.

Discovery of a Potent and Selective Covalent Inhibitor of Bruton's Tyrosine Kinase with Oral Anti-Inflammatory Activity

Bruton's tyrosine kinase (BTK) is a cytoplasmic tyrosine kinase that plays a critical role in the activation of B cells, macrophages, and osteoclasts. Given the key role of these cell types in the pathology of autoimmune disorders, BTK inhibitors have the potential to improve treatment outcomes in multiple diseases. Herein, we report the discovery and characterization of a novel potent and selective covalent 4-oxo-4,5-dihydro-3H-1-thia-3,5,8-triazaacenaphthylene-2-carboxamide BTK inhibitor chemotype. Compound 27 irreversibly inhibits BTK by targeting a noncatalytic cysteine residue (Cys481) for covalent bond formation. Compound 27 is characterized by selectivity for BTK, potent in vivo BTK occupancy that is sustained after it is cleared from systemic circulation, and dose-dependent efficacy at reducing joint inflammation in a rat collagen-induced arthritis model.

822 Lessons Learnt During the COVID-19 Pandemic on Emergency Surgical Admissions in A District General Hospital

Introduction

Coronavirus disease (COVID-19) is an acute severe respiratory distress syndrome which resulted in an unprecedented impact on NHS service provision. We aimed to assess the impact of COVID-19 on general surgical services in a district general hospital.

Method

Electronic health care record data was retrospectively collected from 6th of April to 6th of May for both 2019 and 2020.

Results

Despite fewer referrals and admissions in 2020 (133 vs 177 admissions in 2019), there were more failed discharges (29 vs 17 in 2019) and higher associated costs. Higher numbers of biliary related pathologies and pancreatitis (50 in 2020 vs 25 in 2019), and fewer complaints of non-specific abdominal pain (10 in 2020 vs 22 in 2019) were observed. The use of outpatient investigations decreased by approximately 40% in 2020; however, utilisation of inpatient investigations was comparable.

Conclusions

Better utilisation of outpatient investigations and virtual clinic services may surmount pressures from further peaks of COVID-19. The increase in biliary related cases and pancreatitis may be consequent upon lifestyle changes during lockdown. This merits further investigation and if appropriate, public health intervention. In the absence of an efficacious vaccine, further research would be essential to streamline general surgical services based on clinical risk stratification.

Discovery of PF-06835919: A Potent Inhibitor of Ketohexokinase (KHK) for the Treatment of Metabolic Disorders Driven by the Overconsumption of Fructose

Increased fructose consumption and its subsequent metabolism have been implicated in metabolic disorders such as nonalcoholic fatty liver disease and steatohepatitis (NAFLD/NASH) and insulin resistance. Ketohexokinase (KHK) converts fructose to fructose-1-phosphate (F1P) in the first step of the metabolic cascade. Herein we report the discovery of a first-in-class KHK inhibitor, PF-06835919 (8), currently in phase 2 clinical trials. The discovery of 8 was built upon our originally reported, fragment-derived lead 1 and the recognition of an alternative, rotated binding mode upon changing the ribose-pocket binding moiety from a pyrrolidinyl to an azetidinyl ring system. This new binding mode enabled efficient exploration of the vector directed at the Arg-108 residue, leading to the identification of highly potent 3-azabicyclo[3.1.0]hexane acetic acid-based KHK inhibitors by combined use of parallel medicinal chemistry and structure-based drug design.

Assessing IRAK4 Functions in ABC DLBCL by IRAK4 Kinase Inhibition and Protein Degradation

The interleukin-1 receptor-activated kinase 4 (IRAK4) belongs to the IRAK family of serine/threonine kinases and plays a central role in the innate immune response. However, the function of IRAK4 in tumor growth and progression remains elusive. Here we sought to determine the enzymatic and scaffolding functions of IRAK4 in activated B-cell-like diffuse large B cell lymphoma (ABC DLBCL). We chose a highly selective IRAK4 kinase inhibitor to probe the biological effects of kinase inhibition and developed a series of IRAK4 degraders to evaluate the effects of protein degradation in ABC DLBCL cells. Interestingly, the results demonstrated that neither IRAK4 kinase inhibition nor protein degradation led to cell death or growth inhibition, suggesting a redundant role for IRAK4 in ABC DLBCL cell survival. IRAK4 degraders characterized in this study provide useful tools for understanding IRAK4 protein scaffolding function, which was previously unachievable using pharmacological perturbation.

Pharmacologic Characterization of JNJ-42226314, [1-(4-Fluorophenyl)indol-5-yl]-[3-[4-(thiazole-2-carbonyl)piperazin-1-yl]azetidin-1-yl]methanone, a Reversible, Selective, and Potent Monoacylglycerol Lipase Inhibitor

The serine hydrolase monoacylglycerol lipase (MAGL) is the rate-limiting enzyme responsible for the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG) into arachidonic acid and glycerol. Inhibition of 2-AG degradation leads to elevation of 2-AG, the most abundant endogenous agonist of the cannabinoid receptors (CBs) CB1 and CB2. Activation of these receptors has demonstrated beneficial effects on mood, appetite, pain, and inflammation. Therefore, MAGL inhibitors have the potential to produce therapeutic effects in a vast array of complex human diseases. The present report describes the pharmacologic characterization of [1-(4-fluorophenyl)indol-5-yl]-[3-[4-(thiazole-2-carbonyl)piperazin-1-yl]azetidin-1-yl]methanone (JNJ-42226314), a reversible and highly selective MAGL inhibitor. JNJ-42226314 inhibits MAGL in a competitive mode with respect to the 2-AG substrate. In rodent brain, the compound time- and dose-dependently bound to MAGL, indirectly led to CB1 occupancy by raising 2-AG levels, and raised norepinephrine levels in cortex. In vivo, the compound exhibited antinociceptive efficacy in both the rat complete Freund's adjuvant-induced radiant heat hypersensitivity and chronic constriction injury-induced cold hypersensitivity models of inflammatory and neuropathic pain, respectively. Though 30 mg/kg induced hippocampal synaptic depression, altered sleep onset, and decreased electroencephalogram gamma power, 3 mg/kg still provided approximately 80% enzyme occupancy, significantly increased 2-AG and norepinephrine levels, and produced neuropathic antinociception without synaptic depression or decreased gamma power. Thus, it is anticipated that the profile exhibited by this compound will allow for precise modulation of 2-AG levels in vivo, supporting potential therapeutic application in several central nervous system disorders. SIGNIFICANCE STATEMENT: Potentiation of endocannabinoid signaling activity via inhibition of the serine hydrolase monoacylglycerol lipase (MAGL) is an appealing strategy in the development of treatments for several disorders, including ones related to mood, pain, and inflammation. [1-(4-Fluorophenyl)indol-5-yl]-[3-[4-(thiazole-2-carbonyl)piperazin-1-yl]azetidin-1-yl]methanone is presented in this report to be a novel, potent, selective, and reversible noncovalent MAGL inhibitor that demonstrates dose-dependent enhancement of the major endocannabinoid 2-arachidonoylglycerol as well as efficacy in models of neuropathic and inflammatory pain.

Identification of atopic dermatitis phenotypes with good responses to probiotics (Lactobacillus plantarum CJLP133) in children

The therapeutic effect of probiotics in atopic dermatitis (AD) remains controversial and varies according to the individual patient. We aimed to identify a population of AD patients with a good clinical response to probiotic treatment. We recruited 76 children with a median age of 7.1 years who suffered from moderate to severe AD. After a 2-week washout period, all patients were given Lactobacillus plantarum CJLP133 at a dosage of 1×10¹⁰ colony-forming units once a day for 12 weeks. We measured eosinophil counts in the peripheral blood, the proportion of CD4⁺CD25⁺Foxp3⁺ regulatory T (Treg) cells in CD4⁺ T cells, serum total immunoglobulin E (IgE) levels, and specific IgE against common allergens before the start of the treatment (T1) and at discontinuation (T2). Responders were defined as patients with at least a 30% reduction in the SCORing of AD (SCORAD) index after treatment. There were 36 responders and 40 non-responders after probiotic treatment. The median SCORAD was reduced from 29.5 (range 20.6-46.3) at T1 to 16.4 (range 6.3-30.8) at T2 in the responder group (P<0.001). In multivariable logistic regression analysis, a good clinical response was significantly associated with high total IgE levels (aOR 5.1, 95% CI 1.1-23.6), increased expression of transforming growth factor (TGF)-β (aOR 4.6, 95% CI 1.3-15.9), and a high proportion of Treg cells in CD4⁺ T cells (aOR 3.7, 95% CI 1.1-12.7) at T1. In the responder group, the proportion of Treg cells was significantly increased after 12 weeks of treatment (P=0.004), while TGF-β mRNA expression was decreased (P=0.017). Our results suggest that a subgroup of patients with a specific AD phenotype showing an immunologically active state (high total IgE, increased expression of TGF-β, high numbers of Treg cells) may benefit from probiotic treatment with L. plantarum CJLP133.

Reliability and validity of the Atopic Dermatitis Symptom Score (ADSS)

BACKGROUND

We have developed the Atopic Dermatitis Symptom Score (ADSS) by which patients or parents can easily assess and record AD symptoms on a daily basis in a smartphone application. The aim of this study was to evaluate the reliability and validity of the ADSS.

METHODS

We enrolled 307 children and adolescents with AD. Parents or caregivers were asked to record daily symptoms of the patients (itching, sleep disturbance, erythema, dryness, oozing, and edema) using a scale of 0-4. Statistical analyses consisted of the test-retest reliability, concurrent validity, minimal clinically important difference (MCID), responsiveness, floor or ceiling effects, and screening accuracy. Receiver-operating characteristic analyses were conducted to evaluate the ADSS cutoff point for predicting severe AD (SCORing AD [SCORAD] ≥40).

RESULTS

Test-retest reliability between daytime and night-time ADSS was good (intraclass correlation coefficient, 0.82 [95% CI: 0.70-0.90]). An increase in ADSS was significantly associated with an increase in SCORAD (r = 0.64, P < .0001) (concurrent validity). The MCID was 4.1 points for the ADSS. There was a significant association between changes in ADSS and SCORAD (r = 0.56, P < .0001), indicating good responsiveness. At the optimal ADSS cutoff value of 7.0, sensitivity, specificity, and positive and negative predictive values were 88.4%, 78.6%, 21.1%, and 99.1%, respectively (screening accuracy).

CONCLUSIONS

The ADSS can be a useful tool for self-assessment of skin symptoms in children with AD.

Discovery of Fragment-Derived Small Molecules for in Vivo Inhibition of Ketohexokinase (KHK)

Increased fructose consumption and its subsequent metabolism have been implicated in hepatic steatosis, dyslipidemia, obesity, and insulin resistance in humans. Since ketohexokinase (KHK) is the principal enzyme responsible for fructose metabolism, identification of a selective KHK inhibitor may help to further elucidate the effect of KHK inhibition on these metabolic disorders. Until now, studies on KHK inhibition with small molecules have been limited due to the lack of viable in vivo pharmacological tools. Herein we report the discovery of 12, a selective KHK inhibitor with potency and properties suitable for evaluating KHK inhibition in rat models. Key structural features interacting with KHK were discovered through fragment-based screening and subsequent optimization using structure-based drug design, and parallel medicinal chemistry led to the identification of pyridine 12.

A multicenter study on anaphylaxis caused by peanut, tree nuts, and seeds in children and adolescents

Peanut (PN) and tree nuts (TNs) are common causes of anaphylaxis in Western countries, but no information is available in Korea. To feature clinical characteristics of anaphylaxis caused by PN, TNs, and seeds, a retrospective medical record review was performed in 14 university hospitals in Korea (2009-2013). One hundred and twenty-six cases were identified, with the mean age of 4.9 years. PN, walnut (WN), and pine nut accounted for 32.5%, 41.3%, and 7.1%, respectively. The median values of specific IgE (sIgE) to PN, WN, and pine nut were 10.50, 8.74, and 4.61 kU_A /l, respectively. Among 50 cases managed in the emergency department, 52.0% were treated with epinephrine, 66.0% with steroid, 94.0% with antihistamines, 36.0% with oxygen, and 48.0% with bronchodilator. In conclusion, WN, PN, and pine nut were the three most common triggers of anaphylaxis in Korean children, and anaphylaxis could occur at remarkably low levels of sIgE.

Discovery of a Selective Covalent Inhibitor of Lysophospholipase-like 1 (LYPLAL1) as a Tool to Evaluate the Role of this Serine Hydrolase in Metabolism

Lysophospholipase-like 1 (LYPLAL1) is an uncharacterized metabolic serine hydrolase. Human genome-wide association studies link variants of the gene encoding this enzyme to fat distribution, waist-to-hip ratio, and nonalcoholic fatty liver disease. We describe the discovery of potent and selective covalent small-molecule inhibitors of LYPLAL1 and their use to investigate its role in hepatic metabolism. In hepatocytes, selective inhibition of LYPLAL1 increased glucose production supporting the inference that LYPLAL1 is a significant actor in hepatic metabolism. The results provide an example of how a selective chemical tool can contribute to evaluating a hypothetical target for therapeutic intervention, even in the absence of complete biochemical characterization.

Airborne formaldehyde causes skin barrier dysfunction in atopic dermatitis

BACKGROUND

It remains to be elucidated whether exposure to air pollutants aggravates atopic dermatitis (AD).

OBJECTIVES

This study aimed to evaluate the effects of exposure to formaldehyde for 1 h and 2 h on skin barrier function in both the control and the AD groups.

METHODS

In 41 patients with AD and 34 healthy children, a provocation test was performed in which two different areas of normal-appearing skin on the forearm were stimulated with airborne formaldehyde at 500 μg m(-3) or placebo for 2 h. We measured transepidermal water loss (TEWL) and skin pH, and calculated the percentage change from baseline.

RESULTS

Exposure to formaldehyde increased TEWL in the control group [P < 0·001; median of difference 1·4; interquartile range (IQR) 0·9-1·6] and in the AD group (P < 0·001; median of difference 2·5; IQR 2·0-3·6). The percentage change of TEWL after formaldehyde exposure in the AD group was higher than in the control group (P < 0·001), whereas exposure to placebo showed no differences between both groups. The AD group also demonstrated a higher percentage increase in skin pH after exposure to formaldehyde than the control group (P < 0·001).

CONCLUSIONS

Short-term exposure to formaldehyde causes skin barrier dysfunction in both healthy children and children with AD, and this effect is more prominent in children with AD.

Common polygenic variation and risk for childhood-onset schizophrenia

Childhood-onset schizophrenia (COS) is a rare and severe form of the disorder, with more striking abnormalities with respect to prepsychotic developmental disorders and abnormities in the brain development compared with later-onset schizophrenia. We previously documented that COS patients, compared with their healthy siblings and with adult-onset patients (AOS), carry significantly more rare chromosomal copy number variations, spanning large genomic regions (>100 kb) (Ahn et al. 2014). Here, we interrogated the contribution of common polygenic variation to the genetic susceptibility for schizophrenia. We examined the association between a direct measure of genetic risk of schizophrenia in 130 COS probands and 103 healthy siblings. Using data from the schizophrenia and autism GWAS of the Psychiatric Genomic Consortia, we selected three risk-related sets of single nucleotide polymorphisms from which we conducted polygenic risk score comparisons for COS probands and their healthy siblings. COS probands had higher genetic risk scores of both schizophrenia and autism than their siblings (P<0.05). Given the small sample size, these findings suggest that COS patients have more salient genetic risk than do AOS.

Discovery of Selective Small Molecule Inhibitors of Monoacylglycerol Acyltransferase 3

Inhibition of triacylglycerol (TAG) biosynthetic enzymes has been suggested as a promising strategy to treat insulin resistance, diabetes, dyslipidemia, and hepatic steatosis. Monoacylglycerol acyltransferase 3 (MGAT3) is an integral membrane enzyme that catalyzes the acylation of both monoacylglycerol (MAG) and diacylglycerol (DAG) to generate DAG and TAG, respectively. Herein, we report the discovery and characterization of the first selective small molecule inhibitors of MGAT3. Isoindoline-5-sulfonamide (6f, PF-06471553) selectively inhibits MGAT3 with high in vitro potency and cell efficacy. Because the gene encoding MGAT3 (MOGAT3) is found only in higher mammals and humans, but not in rodents, a transgenic mouse model expressing the complete human MOGAT3 was used to characterize the effects of 6f in vivo. In the presence of a combination of diacylglycerol acyltransferases 1 and 2 (DGAT1 and DGAT2) inhibitors, an oral administration of 6f exhibited inhibition of the incorporation of deuterium-labeled glycerol into TAG in this mouse model. The availability of a potent and selective chemical tool and a humanized mouse model described in this report should facilitate further dissection of the physiological function of MGAT3 and its role in lipid homeostasis.

Selective inhibition of FAAH produces antidiarrheal and antinociceptive effect mediated by endocannabinoids and cannabinoid-like fatty acid amides

BACKGROUND

The endogenous cannabinoid system (ECS) plays a crucial role in multiple physiological processes in the central nervous system and in the periphery. The discovery that selective cannabinoid (CB) receptor agonists exert a potent inhibitory action on gastrointestinal (GI) motility and pain has placed the ECS in the center of attention as a possible target for the treatment of functional GI diseases. However, side effects of CB agonists prompted the search for novel therapeutic targets. Here, the effect of PF-3845, a potent and selective fatty acid amide hydrolase (FAAH) inhibitor in the GI tract was investigated.

METHODS

The effect of PF-3845 on GI motility was characterized in vitro and in vivo, using mouse models that mimic physiological and pathophysiological conditions. The antinociceptive action of PF-3845 was evaluated on the basis of behavioral pain models. Endocannabinoid degradation product levels after inhibition of FAAH were quantified using HPLC-MS/MS.

KEY RESULTS

PF-3845 significantly inhibited mouse colonic motility in vitro and in vivo. Selective inhibition of FAAH reversed hypermotility and reduced pain in mouse models mimicking functional GI disorders. The effects of PF-3845 were mediated by endogenous CBs and non-CB lipophilic compounds via classical (CB1) and atypical CB receptors.

CONCLUSIONS & INFERENCES

These data expand our understanding of the ECS function and provide a novel framework for the development of future potential treatments of functional GI disorders.

Do newly built homes affect rhinitis in children? The ISAAC phase III study in Korea

BACKGROUND

As Korea has experienced rapid economic development, the lifestyles of Koreans have become more Westernized, in terms of urbanization and dietary habits. Also, the prevalences of allergic diseases, such as rhinitis, asthma, and dermatitis, have increased rapidly. This study aimed to identify the factors influencing the symptoms of rhinitis conditions, including rhinitis, allergic rhinitis, overlapped rhinitis, and overlapped allergic rhinitis, among Korean children aged 6-7 years.

METHODS

The study subjects were drawn from participants in the International Study of Asthma and Allergies in Childhood (ISAAC) study in 2010 and were aged 6-7 years. We analysed data for a total of 3804 children.

RESULTS

The prevalences of symptoms suggestive of rhinitis and allergic rhinitis in the previous 12 months were 43.4% and 22.1%, respectively. For overlapped rhinitis and overlapped allergic rhinitis, only 2.5% and 1.9% of the children had overlapping symptoms, having rhinitis with asthma and eczema simultaneously. Gender, a parental history of allergic disease, mould or dampness at home, and the risk factors for 'sick building syndrome' (SBS) were risk factors influencing rhinitis diseases. In particular, a history of moving to a newly built home in the child's infancy was strongly associated with symptoms of all the rhinitis diseases examined.

CONCLUSIONS

This study identified patterns of the prevalence of rhinitis conditions among Korean children that were similar to those reported in Western countries. We confirmed that a history of moving to a newly built home during infancy was associated with a considerable risk of rhinitis conditions.

Mechanistic characterization of a 2-thioxanthine myeloperoxidase inhibitor and selectivity assessment utilizing click chemistry--activity-based protein profiling

Myeloperoxidase (MPO) is a heme peroxidase that catalyzes the production of hypochlorous acid. Despite a high level of interest in MPO as a therapeutic target, there have been limited reports about MPO inhibitors that are suitable for evaluating MPO in pharmacological studies. 2-Thioxanthine, 3-(2-ethoxypropyl)-2-thioxo-2,3-dihydro-1H-purin-6(9H)-one (A), has recently been reported to inhibit MPO by covalently modifying the heme prosthetic group. Here we report a detailed mechanistic characterization demonstrating that A possesses all the distinguishing features of a mechanism-based inactivator. A is a time-dependent MPO inhibitor and displays saturable inactivation kinetics consistent with a two-step mechanism of inactivation and a potency (k(inact)/K(I) ratio) of 8450 ± 780 M⁻¹ s⁻¹. MPO inactivation by A is dependent on MPO catalysis and is protected by substrate. A reduces MPO compound I to compound II with a second-order rate constant of (0.801 ± 0.056) × 10⁶ M⁻¹ s⁻¹, and its irreversible inactivation of MPO occurs prior to release of the activated inhibitory species. Despite its relatively high selectivity against a broad panel of more than 100 individual targets, including enzymes, receptors, transporters, and ion channels, we demonstrate that A labels multiple other protein targets in the presence of MPO. By synthesizing an alkyne analogue of A and utilizing click chemistry-activity-based protein profiling, we present that the MPO-activated inhibitory species can diffuse away to covalently modify other proteins, as reflected by the relatively high partition ratio of A, which we determined to be 15.6. This study highlights critical methods that can guide the discovery and development of next-generation MPO inhibitors.

IgE-mediated anaphylaxis and allergic reactions to idursulfase in patients with Hunter syndrome

BACKGROUND

Enzyme replacement therapy (ERT) with recombinant human idursulfase is effective for the treatment of Hunter syndrome, mucopolysaccharidosis (MPS) type II. However, various adverse events can occur by the infusion of idursulfase. The purpose was to evaluate the occurrence of infusion-related allergic reactions, including anaphylaxis, to idursulfase in patients with MPS II receiving ERT and to elucidate its possible mechanism.

METHODS

A total of 34 patients with MPS II were enrolled to receive ERT with Elaprase(®) at a dose of 0.5 mg/kg intravenously once a week. Information regarding the symptoms, frequency, and timing of anaphylaxis during treatment was analyzed. Presence of anti-idursulfase IgE antibody was assessed by skin prick test (SPT) and enzyme-linked immunosorbent assay (ELISA). Western blotting was performed to confirm the reaction between idursulfase and specific IgE.

RESULTS

Three patients (8.8%) showed anaphylaxis by infusion of idursulfase. No deaths occurred during the study. Anti-idursulfase IgE antibody was detected by SPT and ELISA. Immunoblotting with patients' sera and Elaprase(®) showed a single band of specific IgE binding to the protein around 70 kD, and idursulfase did not display amino acid sequence homology to known allergens. SPT with idursulfase demonstrated positive results in all patients with anaphylaxis. However, we failed to reveal any risk factors for the development of infusion-related immediate-type allergic reactions.

CONCLUSIONS

Anaphylaxis related to infusion of idursulfase is mediated by anti-idursulfase IgE antibody, which might be produced by de novo synthesis. SPT is useful in predicting the occurrence of anti-idursulfase IgE-mediated anaphylaxis during infusion.

Evidence for regulated monoacylglycerol acyltransferase expression and activity in human liver

Intrahepatic lipid accumulation is extremely common in obese subjects and is associated with the development of insulin resistance and diabetes. Hepatic diacylglycerol and triacylglycerol synthesis predominantly occurs through acylation of glycerol-3-phosphate. However, an alternative pathway for synthesizing diacylglycerol from monoacylglycerol acyltransferases (MGAT) could also contribute to hepatic glyceride pools. MGAT activity and the expression of the three genes encoding MGAT enzymes (MOGAT1, MOGAT2, and MOGAT3) were determined in liver biopsies from obese human subjects before and after gastric bypass surgery. MOGAT expression was also assessed in liver of subjects with nonalcoholic fatty liver disease (NAFLD) or control livers. All MOGAT genes were expressed in liver, and hepatic MGAT activity was readily detectable in liver lysates. The hepatic expression of MOGAT3 was highly correlated with MGAT activity, whereas MOGAT1 and MOGAT2 expression was not, and knockdown of MOGAT3 expression attenuated MGAT activity in a liver-derived cell line. Marked weight loss following gastric bypass surgery was associated with a significant reduction in MOGAT2 and MOGAT3 expression, which were also overexpressed in NAFLD subjects. These data suggest that the MGAT pathway is active and dynamically regulated in human liver and could be an important target for pharmacologic intervention for the treatment of obesity-related insulin resistance and NAFLD.

Diffusion MRI findings of cytomegalovirus-associated ventriculitis: a case report

Cytomegalovirus (CMV) ventriculoencephalitis is a rare but serious potential complication of CMV infection in immunocompromised patients. Characteristic diffusion-weighted imaging findings can be helpful for the diagnosis of CMV ventriculitis, as in this case report.

Mechanistic and pharmacological characterization of PF-04457845: a highly potent and selective fatty acid amide hydrolase inhibitor that reduces inflammatory and noninflammatory pain

The endogenous cannabinoid (endocannabinoid) anandamide is principally degraded by the integral membrane enzyme fatty acid amide hydrolase (FAAH). Pharmacological blockade of FAAH has emerged as a potentially attractive strategy for augmenting endocannabinoid signaling and retaining the beneficial effects of cannabinoid receptor activation, while avoiding the undesirable side effects, such as weight gain and impairments in cognition and motor control, observed with direct cannabinoid receptor 1 agonists. Here, we report the detailed mechanistic and pharmacological characterization of N-pyridazin-3-yl-4-(3-{[5-(trifluoromethyl)pyridin-2-yl]oxy}benzylidene)piperidine-1-carboxamide (PF-04457845), a highly efficacious and selective FAAH inhibitor. Mechanistic studies confirm that PF-04457845 is a time-dependent, covalent FAAH inhibitor that carbamylates FAAH's catalytic serine nucleophile. PF-04457845 inhibits human FAAH with high potency (k(inact)/K(i) = 40,300 M(-1)s(-1); IC(50) = 7.2 nM) and is exquisitely selective in vivo as determined by activity-based protein profiling. Oral administration of PF-04457845 produced potent antinociceptive effects in both inflammatory [complete Freund's adjuvant (CFA)] and noninflammatory (monosodium iodoacetate) pain models in rats, with a minimum effective dose of 0.1 mg/kg (CFA model). PF-04457845 displayed a long duration of action as a single oral administration at 1 mg/kg showed in vivo efficacy for 24 h with a concomitant near-complete inhibition of FAAH activity and maximal sustained elevation of anandamide in brain. Significantly, PF-04457845-treated mice at 10 mg/kg elicited no effect in motility, catalepsy, and body temperature. Based on its exceptional selectivity and in vivo efficacy, combined with long duration of action and optimal pharmacokinetic properties, PF-04457845 is a clinical candidate for the treatment of pain and other nervous system disorders.

Discovery of PF-04457845: A Highly Potent, Orally Bioavailable, and Selective Urea FAAH Inhibitor

Fatty acid amide hydrolase (FAAH) is an integral membrane serine hydrolase that degrades the fatty acid amide family of signaling lipids, including the endocannabinoid anandamide. Genetic or pharmacological inactivation of FAAH leads to analgesic and anti-inflammatory phenotypes in rodents without showing the undesirable side effects observed with direct cannabinoid receptor agonists, indicating that FAAH may represent an attractive therapeutic target for the treatment of inflammatory pain and other nervous system disorders. Herein, we report the discovery and characterization of a highly efficacious and selective FAAH inhibitor PF-04457845 (23). Compound 23 inhibits FAAH by a covalent, irreversible mechanism involving carbamylation of the active-site serine nucleophile of FAAH with high in vitro potency (k(inact)/K(i) and IC(50) values of 40300 M(-1) s(-1) and 7.2 nM, respectively, for human FAAH). Compound 23 has exquisite selectivity for FAAH relative to other members of the serine hydrolase superfamily as demonstrated by competitive activity-based protein profiling. Oral administration of 23 at 0.1 mg/kg results in efficacy comparable to that of naproxen at 10 mg/kg in a rat model of inflammatory pain. Compound 23 is being evaluated in human clinical trials.

[Emergency operation and hypothermic therapy for Stanford type A acute aortic dissection in the state of coma]

We report of a 77-year-old woman who was admitted to our hospital in coma by emergency. A computed tomography scan revealed acute aortic dissection (Stanford type A). We established selective antegrade cerebral perfusion within 3 hours of the onset and then performed ascending aortic replacement. In the state of hypothermia (35 degrees C), the patient was weaned from cardiopulmonary bypass. The patient was kept hypothermic until the operation was completed. We kept mild hypothermia (34.5 degrees C) in intensive care unit (ICU) for 40 hours. The patient was extubated at 94 hours after the operation. The patient was discharged from the hospital on foot on postoperative day 21.

Netrin-1: a novel universal biomarker of human kidney injury

Currently available diagnostic markers representing kidney injury or function such as serum creatinine and blood urea nitrogen are insensitive and often increased late in the disease process. Netrin-1 protein, a laminin-related secreted molecule, is minimally or not expressed in tubular epithelial cells of normal kidneys. However, it is highly expressed in injured kidneys. Netrin-1 protein has been shown to be detected in urine from mice with acute kidney injury. The current study was carried out to evaluate whether netrin-1 is also induced in human acute kidney injury (AKI) and can serve as a urinary biomarker of the condition. We analyzed netrin-1 levels by sandwich enzyme-linked immunosorbent assay in urine samples from 10 healthy controls, 22 recipients of a renal allograft, 11 patients with ischemic AKI, 13 with AKI associated with sepsis, 9 with radiocontrast-induced AKI, and 8 with drug-induced AKI. Urinary netrin-1 levels normalized for urinary creatinine were significantly higher in all subject groups. The highest values were observed in patients with sepsis and in transplant patients immediately postoperatively. The level of NGAL was similarly increased in transplant patients. In conclusion, urinary netrin-1 levels are increased in patients with various forms of AKI/ATN and may serve as a universal biomarker for AKI.