Complement factor B is critical for sub-RPE deposit accumulation in a model of Doyne honeycomb retinal dystrophy with features of age-related macular degeneration.

EFEMP1 R345W is a dominant mutation causing Doyne honeycomb retinal dystrophy/malattia leventinese (DHRD/ML), a rare blinding disease with clinical pathology similar to age-related macular degeneration (AMD). Aged Efemp1  R345W/R345W knock-in mice (Efemp1ki/ki) develop microscopic deposits on the basal side of retinal pigment epithelial cells (RPE), an early feature in DHRD/ML and AMD. Here, we assessed the role of alternative complement pathway component factor B (FB) in the formation of these deposits. RNA-seq analysis of the posterior eyecups revealed increased unfolded protein response, decreased mitochondrial function in the neural retina (by 3 months of age) and increased inflammatory pathways in both neural retina and posterior eyecups (at 17 months of age) of Efemp1ki/ki mice compared with wild-type littermate controls. Proteomics analysis of eye lysates confirmed similar dysregulated pathways as detected by RNA-seq. Complement activation was increased in aged Efemp1ki/ki eyes with an approximately 2-fold elevation of complement breakdown products iC3b and Ba (P < 0.05). Deletion of the Cfb gene in female Efemp1ki/ki mice partially normalized the above dysregulated biological pathway changes and oral dosing of a small molecule FB inhibitor from 10 to 12 months of age reduced sub-RPE deposits by 65% (P = 0.029). In contrast, male Efemp1ki/ki mice had fewer sub-RPE deposits than age-matched females, no elevation of ocular complement activation and no effect of FB inhibition on sub-RPE deposits. The effects of FB deletion or inhibition on Efemp1ki/ki mice supports systemic inhibition of the alternative complement pathway as a potential treatment of dry AMD and DHRD/ML.

Discovery of 4-((2S,4S)-4-Ethoxy-1-((5-methoxy-7-methyl-1H-indol-4-yl)methyl)piperidin-2-yl)benzoic Acid (LNP023), a Factor B Inhibitor Specifically Designed To Be Applicable to Treating a Diverse Array of Complement Mediated Diseases.

The alternative pathway (AP) of the complement system is a key contributor to the pathogenesis of several human diseases including age-related macular degeneration, paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), and various glomerular diseases. The serine protease factor B (FB) is a key node in the AP and is integral to the formation of C3 and C5 convertase. Despite the prominent role of FB in the AP, selective orally bioavailable inhibitors, beyond our own efforts, have not been reported previously. Herein we describe in more detail our efforts to identify FB inhibitors by high-throughput screening (HTS) and leveraging insights from several X-ray cocrystal structures during optimization efforts. This work culminated in the discovery of LNP023 (41), which is currently being evaluated clinically in several diverse AP mediated indications.

Design, Synthesis, and Preclinical Characterization of Selective Factor D Inhibitors Targeting the Alternative Complement Pathway.

Complement factor D (FD), a highly specific S1 serine protease, plays a central role in the amplification of the alternative complement pathway (AP) of the innate immune system. Dysregulation of AP activity predisposes individuals to diverse disorders such as age-related macular degeneration, atypical hemolytic uremic syndrome, membranoproliferative glomerulonephritis type II, and paroxysmal nocturnal hemoglobinuria. Previously, we have reported the screening efforts and identification of reversible benzylamine-based FD inhibitors (1 and 2) binding to the open active conformation of FD. In continuation of our drug discovery program, we designed compounds applying structure-based approaches to improve interactions with FD and gain selectivity against S1 serine proteases. We report herein the design, synthesis, and medicinal chemistry optimization of the benzylamine series culminating in the discovery of 12, an orally bioavailable and selective FD inhibitor. 12 demonstrated systemic suppression of AP activation in a lipopolysaccharide-induced AP activation model as well as local ocular suppression in intravitreal injection-induced AP activation model in mice expressing human FD.

Small-molecule factor B inhibitor for the treatment of complement-mediated diseases.

Dysregulation of the alternative complement pathway (AP) predisposes individuals to a number of diseases including paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, and C3 glomerulopathy. Moreover, glomerular Ig deposits can lead to complement-driven nephropathies. Here we describe the discovery of a highly potent, reversible, and selective small-molecule inhibitor of factor B, a serine protease that drives the central amplification loop of the AP. Oral administration of the inhibitor prevents KRN-induced arthritis in mice and is effective upon prophylactic and therapeutic dosing in an experimental model of membranous nephropathy in rats. In addition, inhibition of factor B prevents complement activation in sera from C3 glomerulopathy patients and the hemolysis of human PNH erythrocytes. These data demonstrate the potential therapeutic value of using a factor B inhibitor for systemic treatment of complement-mediated diseases and provide a basis for its clinical development.

Amount of Mononuclear Phagocyte Infiltrate Does Not Predict Area of Experimental Choroidal Neovascularization (CNV).

PURPOSE: Mononuclear phagocytes (MNPs) are present in neovascular age-related macular degeneration (nv AMD) which is also called choroidal neovascularization (CNV). The number and phenotype of the MNPs depend upon the local environment in the CNV and effect of nv AMD therapy. We investigated ocular cell infiltration and conditions that modulate angiogenesis in a laser-induced mouse CNV model. METHODS: We developed assays to quantify MNPs in our established mouse CNV model. One MNP assay quantified the number of subretinal cells peripheral to the CNV lesions. A second assay semiquantitatively assesses the number of MNPs localized to the CNV lesion. We used these assays to measure the effect of toll-like receptor-2 (TLR-2) activation, anti-vascular endothelial growth factor (VEGF) therapy, and chemokine (C-C motif) ligand 2 (Ccl2) genetic deletion on MNP infiltration after laser injury. RESULTS: Laser injury induced blood vessel growth and infiltration of MNPs. Systemic administration of a TLR-2 activating peptide increased laser-induced CNV area, MNP cell numbers, and MNP density over the CNV lesions. Systemic administration of a VEGF antibody reduced CNV area, while Ccl2 genetic deletion increased CNV area. Despite the change in amount of angiogenesis, MNP infiltration was, surprisingly, unchanged in these 2 conditions. CONCLUSIONS: MNP quantification provides biological insights for candidate AMD therapies. The number of infiltrating MNP cells does not correlate with the amount of laser-induced CNV area.

Induction of Ocular Complement Activation by Inflammatory Stimuli and Intraocular Inhibition of Complement Factor D in Animal Models.

Purpose: Genome-wide association studies suggest a role for the complement system in age-related macular degeneration (AMD). We characterized ocular complement activation and evaluated a complement factor D (FD) neutralizing antibody. Methods: Mice were treated with toll-like receptor (TLR) ligands, intravitreal injection (IVT), or corneal debridement. Levels of complement proteins and mRNA were measured. A FD neutralizing antibody was administered IVT into eyes of rabbits that were challenged with LPS (lipopolysaccharide) administered intravenously. Results: Levels of C3 and factor B (FB) mRNA and protein in the eye were increased following intraperitoneal injection of TLR4 ligand LPS. Increased levels of C3 and FB breakdown products were observed in both eye tissues and plasma. Complement activation products were markedly reduced in C3-/- and Cfb-/- mice challenged with LPS. Ocular complement levels were also elevated in mice treated systemically with TLR2 and -3 ligands, injured by IVT injection or corneal debridement, or even in normal aging. IVT administration of a complement FD neutralizing antibody in rabbits inhibited LPS-induced complement activation in the posterior segment of the eye, but not in the anterior segment of the eye or in plasma. Conclusions: Systemic TLR stimulation and eye tissue injury induced time-dependent alternative complement pathway activation in the eye. Ocular complement levels were also gradually elevated during aging. An anti-FD antibody IVT potently inhibited LPS-induced complement activation in the posterior segment of the eye. This study provides insights into the dynamic profile of ocular complement activation, which is valuable for complement research in eye diseases and for developing complement therapeutics for AMD.

The Discovery of N-(1-Methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)-5-((6- ((methylamino)methyl)pyrimidin-4-yl)oxy)-1H-indole-1-carboxamide (Acrizanib), a VEGFR-2 Inhibitor Specifically Designed for Topical Ocular Delivery, as a Therapy for Neovascular Age-Related Macular Degeneration.

A noninvasive topical ocular therapy for the treatment of neovascular or "wet" age-related macular degeneration would provide a patient administered alternative to the current standard of care, which requires physician administered intravitreal injections. This manuscript describes a novel strategy for the use of in vivo models of choroidal neovascularization (CNV) as the primary means of developing SAR related to efficacy from topical administration. Ultimately, this effort led to the discovery of acrizanib (LHA510), a small-molecule VEGFR-2 inhibitor with potency and efficacy in rodent CNV models, limited systemic exposure after topical ocular administration, multiple formulation options, and an acceptable rabbit ocular PK profile.

Nonclinical Safety Evaluation of scAAV8-RLBP1 for Treatment of RLBP1 Retinitis Pigmentosa.

Retinitis pigmentosa is a form of retinal degeneration usually caused by genetic mutations affecting key functional proteins. We have previously demonstrated efficacy in a mouse model of RLBP1 deficiency with a self-complementary AAV8 vector carrying the gene for human RLBP1 under control of a short RLBP1 promoter (CPK850).1 In this article, we describe the nonclinical safety profile of this construct as well as updated efficacy data in the intended clinical formulation. In Rlbp1-/- mice dosed at a range of CPK850 levels, a minimum efficacious dose of 3 × 107 vg in a volume of 1 µL was observed. For safety assessment in these and Rlbp1+/+ mice, optical coherence tomography (OCT) and histopathological analysis indicated retinal thinning that appeared to be dose-dependent for both Rlbp1 genotypes, with no qualitative difference noted between Rlbp1+/+ and Rlbp1-/- mice. In a non-human primate study, RLBP1 mRNA expression was detected and dose dependent intraocular inflammation and retinal thinning were observed. Inflammation resolved slowly over time and did not appear to be exacerbated in the presence of anti-AAV8 antibodies. Biodistribution was evaluated in rats and satellite animals in the non-human primate study. The vector was largely detected in ocular tissues and low levels in the optic nerve, superior colliculus, and lateral geniculate nucleus, with limited distribution outside of these tissues. These data suggest that an initial subretinal dose of ∼3 × 107 vg/µL CPK850 can safely be used in clinical trials.

Discovery of Highly Potent and Selective Small-Molecule Reversible Factor D Inhibitors Demonstrating Alternative Complement Pathway Inhibition in Vivo.

The highly specific S1 serine protease factor D (FD) plays a central role in the amplification of the complement alternative pathway (AP) of the innate immune system. Genetic associations in humans have implicated AP activation in age-related macular degeneration (AMD), and AP dysfunction predisposes individuals to disorders such as paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS). The combination of structure-based hit identification and subsequent optimization of the center (S)-proline-based lead 7 has led to the discovery of noncovalent reversible and selective human factor D (FD) inhibitors with drug-like properties. The orally bioavailable compound 2 exerted excellent potency in 50% human whole blood in vitro and blocked AP activity ex vivo after oral administration to monkeys as demonstrated by inhibition of membrane attack complex (MAC) formation. Inhibitor 2 demonstrated sustained oral and ocular efficacy in a model of lipopolysaccharide (LPS)-induced systemic AP activation in mice expressing human FD.

Specific correlation between the major chromosome 10q26 haplotype conferring risk for age-related macular degeneration and the expression of HTRA1.

PURPOSE: A region within chromosome 10q26 has a set of single nucleotide polymorphisms (SNPs) that define a haplotype that confers high risk for age-related macular degeneration (AMD). We used a bioinformatics approach to search for genes in this region that may be responsible for risk for AMD by assessing levels of gene expression in individuals carrying different haplotypes and by searching for open chromatin regions in the retinal pigment epithelium (RPE) that might include one or more of the SNPs. METHODS: We surveyed the PubMed and the 1000 Genomes databases to find all common (minor allele frequency > 0.01) SNPs in 10q26 strongly associated with AMD. We used the HaploReg and LDlink databases to find sets of SNPs with alleles in linkage disequilibrium and used the Genotype-Tissue Expression (GTEx) database to search for correlations between genotypes at individual SNPs and the relative level of expression of the genes. We also accessed Encyclopedia of DNA Elements (ENCODE) to find segments of open chromatin in the region with the AMD-associated SNPs. Predicted transcription factor binding motifs were identified using HOMER, PROMO, and RegulomeDB software programs. RESULTS: There are 34 polymorphisms within a 30-kb region that are in strong linkage disequilibrium (r2>0.8) with the reference SNP rs10490924 previously associated with risk for AMD. The expression of three genes in this region, PLEKHA1, ARMS2, and HTRA1 varies between people who have the low-AMD-risk haplotype compared with those with the high-AMD-risk haplotype. For PLEKHA1, 44 tissues have an expression pattern with the high-AMD-risk haplotype associated with low expression (rs10490924 effect size -0.43, p = 3.8 x 10-5 in ovary). With regard to ARMS2, the variation is most pronounced in testes: homozygotes with the high-AMD-risk haplotype express ARMS2 at lower levels than homozygotes with the low-AMD-risk haplotype; expression in heterozygotes falls in between (rs10490924 effect size -0.79, p = 7.5 x 10-24). For HTRA1, the expression pattern is the opposite; the high-AMD-risk haplotype has higher levels of expression in 27 tissues (rs10490924 effect size 0.40, p = 1.5 × 10-7 in testes). None of the other 22 genes within one megabase of rs10490924, or any gene in the entire genome, have mRNA expression levels that correlate with the high-AMD-risk haplotype. More than 100 other SNPs in the 10q26 region affect the expression of PLEKHA1 and ARMS2 but not that of HTRA1; none of these SNPs affects the risk for AMD according to published genome-wide association studies (GWASs). Two of the AMD-risk SNPs (rs36212732 and rs36212733) affect transcription factor binding sites in proximity to a DNase I hypersensitive region (i.e., a region of open chromatin) in RPE cells. CONCLUSIONS: SNPs in chromosome 10q26 that influence the expression of only PLEKHA1 or ARMS2 are not associated with risk for AMD, while most SNPs that influence the expression of HTRA1 are associated with risk for AMD. Two of the AMD-risk SNPs affect transcription factor binding sites that may control expression of one of the linked genes in the RPE. These findings suggest that the variation in the risk for AMD associated with chromosome 10q26 is likely due to variation in HTRA1 expression. Modulating HTRA1 activity might be a potential therapy for AMD.

Long-acting protein drugs for the treatment of ocular diseases.

Protein drugs that neutralize vascular endothelial growth factor (VEGF), such as aflibercept or ranibizumab, rescue vision in patients with retinal vascular diseases. Nonetheless, optimal visual outcomes require intraocular injections as frequently as every month. Here we report a method to extend the intravitreal half-life of protein drugs as an alternative to either encapsulation or chemical modifications with polymers. We combine a 97-amino-acid peptide of human origin that binds hyaluronan, a major macromolecular component of the eye's vitreous, with therapeutic antibodies and proteins. When administered to rabbit and monkey eyes, the half-life of the modified proteins is increased ∼3-4-fold relative to unmodified proteins. We further show that prototype long-acting anti-VEGF drugs (LAVAs) that include this peptide attenuate VEGF-induced retinal changes in animal models of neovascular retinal disease ∼3-4-fold longer than unmodified drugs. This approach has the potential to reduce the dosing frequency associated with retinal disease treatments.

Small-molecule factor D inhibitors targeting the alternative complement pathway.

Complement is a key component of the innate immune system, recognizing pathogens and promoting their elimination. Complement component 3 (C3) is the central component of the system. Activation of C3 can be initiated by three distinct routes-the classical, the lectin and the alternative pathways-with the alternative pathway also acting as an amplification loop for the other two pathways. The protease factor D (FD) is essential for this amplification process, which, when dysregulated, predisposes individuals to diverse disorders including age-related macular degeneration and paroxysmal nocturnal hemoglobinuria (PNH). Here we describe the identification of potent and selective small-molecule inhibitors of FD. These inhibitors efficiently block alternative pathway (AP) activation and prevent both C3 deposition onto, and lysis of, PNH erythrocytes. Their oral administration inhibited lipopolysaccharide-induced AP activation in FD-humanized mice. These data demonstrate the feasibility of inhibiting the AP with small-molecule antagonists and support the development of FD inhibitors for the treatment of complement-mediated diseases.

Discovery of Oral VEGFR-2 Inhibitors with Prolonged Ocular Retention That Are Efficacious in Models of Wet Age-Related Macular Degeneration.

The benefit of intravitreal anti-VEGF therapy in treating wet age-related macular degeneration (AMD) is well established. Identification of VEGFR-2 inhibitors with optimal ADME properties for an ocular indication provides opportunities for dosing routes beyond intravitreal injection. We employed a high-throughput in vivo screening strategy with rodent models of choroidal neovascularization and iterative compound design to identify VEGFR-2 inhibitors with potential to benefit wet AMD patients. These compounds demonstrate preferential ocular tissue distribution and efficacy after oral administration while minimizing systemic exposure.

AAV-mediated RLBP1 gene therapy improves the rate of dark adaptation in Rlbp1 knockout mice.

Recessive mutations in RLBP1 cause a form of retinitis pigmentosa in which the retina, before its degeneration leads to blindness, abnormally slowly recovers sensitivity after exposure to light. To develop a potential gene therapy for this condition, we tested multiple recombinant adeno-associated vectors (rAAVs) composed of different promoters, capsid serotypes, and genome conformations. We generated rAAVs in which sequences from the promoters of the human RLBP1, RPE65, or BEST1 genes drove the expression of a reporter gene (green fluorescent protein). A promoter derived from the RLBP1 gene mediated expression in the retinal pigment epithelium and Müller cells (the intended target cell types) at qualitatively higher levels than in other retinal cell types in wild-type mice and monkeys. With this promoter upstream of the coding sequence of the human RLBP1 gene, we compared the potencies of vectors with an AAV2 versus an AAV8 capsid in transducing mouse retinas, and we compared vectors with a self-complementary versus a single-stranded genome. The optimal vector (scAAV8-pRLBP1-hRLBP1) had serotype 8 capsid and a self-complementary genome. Subretinal injection of scAAV8-pRLBP1-hRLBP1 in Rlbp1 nullizygous mice improved the rate of dark adaptation based on scotopic (rod-plus-cone) and photopic (cone) electroretinograms (ERGs). The effect was still present after 1 year.

Lack of involvement of CEP adducts in TLR activation and in angiogenesis.

Proteins that are post-translationally adducted with 2-(ω-carboxyethyl)pyrrole (CEP) have been proposed to play a pathogenic role in age-related macular degeneration, by inducing angiogenesis in a Toll Like Receptor 2 (TLR2)-dependent manner. We have investigated the involvement of CEP adducts in angiogenesis and TLR activation, to assess the therapeutic potential of inhibiting CEP adducts and TLR2 for ocular angiogenesis. As tool reagents, several CEP-adducted proteins and peptides were synthetically generated by published methodology and adduction was confirmed by NMR and LC-MS/MS analyses. Structural studies showed significant changes in secondary structure in CEP-adducted proteins but not the untreated proteins. Similar structural changes were also observed in the treated unadducted proteins, which were treated by the same adduction method except for one critical step required to form the CEP group. Thus some structural changes were unrelated to CEP groups and were artificially induced by the synthesis method. In biological studies, the CEP-adducted proteins and peptides failed to activate TLR2 in cell-based assays and in an in vivo TLR2-mediated retinal leukocyte infiltration model. Neither CEP adducts nor TLR agonists were able to induce angiogenesis in a tube formation assay. In vivo, treatment of animals with CEP-adducted protein had no effect on laser-induced choroidal neovascularization. Furthermore, in vivo inactivation of TLR2 by deficiency in Myeloid Differentiation factor 88 (Myd88) had no effect on abrasion-induced corneal neovascularization. Thus the CEP-TLR2 axis, which is implicated in other wound angiogenesis models, does not appear to play a pathological role in a corneal wound angiogenesis model. Collectively, our data do not support the mechanism of action of CEP adducts in TLR2-mediated angiogenesis proposed by others.

Reliability of the mouse model of choroidal neovascularization induced by laser photocoagulation.

PURPOSE: We attempted to reproduce published studies that evaluated whether the following factors influence choroidal neovascularization (CNV) induced by laser photocoagulation in murine retinas: small interfering RNA (siRNA), cobra venom factor, complement factors C3 and C5, and complement receptor C5aR. In addition, we explored whether laser-induced CNV in mice was influenced by the vendor of origin of the animals. METHODS: Reagents or genotypes reported by others to influence CNV in this model were assessed using our standard procedures. Retrospective analyses of control or placebo mice in many experiments were done to evaluate whether the CNV area induced by laser photocoagulation varied according to vendor. RESULTS: Administration of the following agents did not have a substantial impact on the CNV induced by laser burns in mice: siRNA, low-molecular-weight inhibitor of the C5a receptor (PMX53), or cobra venom factor. Jackson Laboratory (JAX) mice lacking either C3 or C5 had increased neovascularization compared to non-littermate JAX wild-type controls. Taconic mice lacking C3 had reduced CNV compared to non-littermate Taconic wild-type control mice. A retrospective analysis of vehicle-treated wild-type C57BL/6 mice used as controls across 132 experiments conducted from 2007 to 2010 revealed that mice purchased from JAX or from Charles River produced less neovascularization than mice from Taconic. CONCLUSIONS: We present our recommended methods for conducting experiments with the mouse laser-induced CNV model to enhance reproducibility and minimize investigator bias.

An effective prodrug strategy to selectively enhance ocular exposure of a cannabinoid receptor (CB1/2) agonist.

Glaucoma is a leading cause of vision loss and blindness, with increased intraocular pressure (IOP) a prominent risk factor. IOP can be efficaciously reduced by administration of topical agents. However, the repertoire of approved IOP-lowering drug classes is limited, and effective new alternatives are needed. Agonism of the cannabinoid receptors CB1/2 significantly reduces IOP clinically and experimentally. However, development of CB1/2 agonists has been complicated by the need to avoid cardiovascular and psychotropic side effects. 1 is a potent CB1/2 agonist that is highly excluded from the brain. In a phase I study, compound 1 eyedrops were well tolerated and generated an IOP-lowering trend but were limited in dose and exposure due to poor solubility and ocular absorption. Here we present an innovative strategy to rapidly identify compound 1 prodrugs that are efficiently metabolized to the parent compound for improved solubility and ocular permeability while maintaining low systemic exposures.

Pharmacologic uncoupling of angiogenesis and inflammation during initiation of pathological corneal neovascularization.

Pathological neovascularization occurs when a balance of pro- and anti-angiogenic factors is disrupted, accompanied by an amplifying inflammatory cascade. However, the interdependence of these responses and the mechanism triggering the initial angiogenic switch have remained unclear. We present data from an epithelial debridement model of corneal neovascularization describing an initial 3-day period when a substantial component of neovascular growth occurs. Administration of selective inhibitors shows that this initial growth requires signaling through VEGFR-2 (vascular endothelial growth factor receptor-2), independent of the accompanying inflammatory response. Instead, increased VEGF production is found prominently in repair epithelial cells and is increased prior to recruitment of neutrophil/granulocytes and macrophage/monocytes. Consequently, early granulocyte and monocyte depletion has little effect on corneal neovascularization outgrowth. These data indicate that it is possible to pharmacologically uncouple these mechanisms during early injury-driven neovascularization in the cornea and suggest that initial tissue responses are coordinated by repair epithelial cells.

PCR primers with enhanced specificity for nematode-trapping fungi (Orbiliales).

Nematode-trapping fungi, a monophyletic lineage within the Orbiliales (Ascomycota), use specialized structures to capture and consume nematodes in soil, leaf litter, and other substrates. These fungi have been studied both because of their unique predatory life history and because they are potential control agents of important plant- and animal-parasitic nematodes. Ecological studies of nematode-trapping fungi have primarily used culture-based methods, but molecular detection techniques are now available and should be useful for studying this group. We developed Orbiliales-specific PCR primers for the ITS and 28s rDNA to directly detect nematode-trapping fungi without culturing and also to screen fungal isolates for phylogenetic placement in the Orbiliales. We used these primers to selectively amplify, clone, and sequence Orbiliales DNA extracted from soil, litter, and wood, and we compared the results of molecular detection with those obtained using a culture-based method. Of the eight species of nematode-trapping Orbiliales detected with the culture-based assay, only three were detected with PCR. The molecular assay, however, detected 18 species of uncultured Orbiliales, many of which are closely related to nematode-trapping fungi and fungal parasites of nematode eggs. Our results suggest that the combined use of Orbiliales-specific primers and culture-based techniques may benefit future studies of nematophagous fungi.

Selective cell adhesion inhibitors: Barbituric acid based alpha4beta7--MAdCAM inhibitors.

A novel series of barbituric acid derivatives were identified as selective inhibitors of alpha4beta7 MAdCAM (mucosal addressin cell adhesion molecule-1) interactions via a high throughput screening exercise. These inhibitors were optimized to submicromolar potencies in whole cell adhesion assays, retaining their selectivity over alpha4beta1 VCAM.