Vercirnon for the treatment of Crohn's disease

Biased agonism at chemokine receptors

In the human chemokine system, interactions between the approximately 50 known endogenous chemokine ligands and 20 known chemokine receptors (CKRs) regulate a wide range of cellular functions and biological processes including immune cell activation and homeostasis, development, angiogenesis, and neuromodulation. CKRs are a family of G protein-coupled receptors (GPCR), which represent the most common and versatile class of receptors in the human genome and the targets of approximately one third of all Food and Drug Administration-approved drugs. Chemokines and CKRs bind with significant promiscuity, as most CKRs can be activated by multiple chemokines and most chemokines can activate multiple CKRs. While these ligand-receptor interactions were previously regarded as redundant, it is now appreciated that many chemokine:CKR interactions display biased agonism, the phenomenon in which different ligands binding to the same receptor signal through different pathways with different efficacies, leading to distinct biological effects. Notably, these biased responses can be modulated through changes in ligand, receptor, and or the specific cellular context (system). In this review, we explore the biochemical mechanisms, functional consequences, and therapeutic potential of biased agonism in the chemokine system. An enhanced understanding of biased agonism in the chemokine system may prove transformative in the understanding of the mechanisms and consequences of biased signaling across all GPCR subtypes and aid in the development of biased pharmaceuticals with increased therapeutic efficacy and safer side effect profiles.

Inflammatory Markers in Suction Blister Fluid: A Comparative Study Between Interstitial Fluid and Plasma

Background

Biomarker analysis allows for the detection and prediction of disease as well as health monitoring. The use of interstitial fluid (ISF) as a matrix for biomarkers has recently gained interest. This study aimed to compare levels of inflammatory markers in ISF from suction blister fluid (SBF) and plasma.

Methods

Plasma and SBF were collected from 18 healthy individuals. Samples were analyzed for 92 inflammation-related protein biomarkers by Proximity Extension Assay (PEA). Protein profiles in the two matrices were compared using traditional and multivariate statistics.

Results

Out of 92 targeted proteins, 70 were successfully quantified in both plasma and SBF. Overall, plasma and SBF displayed distinct protein profiles with up to 40-fold difference in abundance of specific proteins. The levels of 25 proteins were significantly correlated between plasma and SBF and several of these were recognized as potential markers to monitor health using ISF.

Conclusions

Skin ISF and plasma have unique protein profiles but many inflammatory markers are proportionally related between the matrices at the individual level. ISF is a promising biofluid for the monitoring of biomarkers in clinical studies and routine analyses.

Novel Pharmacological Therapy in Inflammatory Bowel Diseases: Beyond Anti-Tumor Necrosis Factor

Inflammatory bowel diseases (IBDs) are chronic conditions of the gastrointestinal tract in which dysregulated immune responses cause persistent inflammation of the gut mucosa. Biologic therapy with anti-TNF blockers has revolutionized the therapeutic management of IBD for their remarkable efficacy and potential impact on disease course and for many years has represented the sole treatment option for patients refractory or intolerant to conventional therapy. In recent years, more molecules, both biologically and chemically synthetized, have been developed as potential therapeutic options for IBD that target different molecular pathways aside from TNF blockade, and which have been proposed as targets for novel drugs. This is particularly relevant for the present, as well as future, management of IBD, considering that some patients are refractory to anti-TNF. This review will summarize the pharmacological options, either currently available or in the pipeline, for market approval to treat IBD, besides anti-TNF strategies, based on their mechanism(s) of action. We will also analyze the current evidence for effectiveness and safety, as well as offer perspective, regarding the potential implementation for such therapies in the future.

Nonconjugated Hydrocarbons as Rigid-Linear Motifs: Isosteres for Material Sciences and Bioorganic and Medicinal Chemistry

Nonconjugated hydrocarbons, like bicyclo[1.1.1]pentane, bicyclo[2.2.2]octane, triptycene, and cubane are a unique class of rigid linkers. Due to their similarity in size and shape they are useful mimics of classic benzene moieties in drugs, so-called bioisosteres. Moreover, they also fulfill an important role in material sciences as linear linkers, in order to arrange various functionalities in a defined spatial manner. In this Review article, recent developments and usages of these special, rectilinear systems are discussed. Furthermore, we focus on covalently linked, nonconjugated linear arrangements and discuss the physical and chemical properties and differences of individual linkers, as well as their application in material and medicinal sciences.

Natalizumab in the treatment of Crohn's disease patients

INTRODUCTION

Amongst the available therapies for moderate to severe Crohn's disease (CD) patients who are refractory to conventional therapy, anti-TNF blockers are the most effective biological treatment option. However, many patients experience a primary or secondary non-response to anti-TNF therapy, creating the need for alternative biological drugs that target different mechanisms of action and inflammatory pathways. Natalizumab, the first non-anti-TNF biological drug to be approved for treatment of CD patients, is a recombinant humanized antibody that targets the α₄-subunit of both α₄β₁ and α₄β₇ integrins, thus preventing activated leukocyte homing to the intestinal mucosa. Areas covered: This article summarizes the pathophysiological background and the efficacy and safety data of natalizumab, as well as the regulatory issues surrounding it. Expert opinion: Natalizumab represents an effective therapy for refractory CD patients. However, the rare but serious event of progressive multifocal leukoencephalopathy occurrence has compromised its widespread use. The subsequent advent of more specific anti-integrin drugs (i.e. vedolizumab) that carry a more favorable safety profile further reduces the clinical indications for natalizumab. The regulatory process for natalizumab distribution and monitoring in the US may provide a forum for discussion on how to optimally manage use of drugs that offer clinical benefits to patients, while minimizing associated risks.

Recent insights into the molecular pathogenesis of Crohn's disease: a review of emerging therapeutic targets

Chronic inflammatory bowel diseases (IBDs) are a subject of great interest in gastroenterology, due to a pathological mechanism that is difficult to explain and an optimal therapeutic approach still undiscovered. Crohn's disease (CD) is one of the main entities in IBD, characterized by clinical polymorphism and great variability in the treatment response. Modern theories on the pathogenesis of CD have proven that gut microbiome and environmental factors lead to an abnormal immune response in a genetically predisposed patient. Genome-wide association studies in patients with CD worldwide revealed several genetic mutations that increase the risk of IBD and that predispose to a more severe course of disease. Gut microbiota is considered a compulsory and an essential part in the pathogenesis of CD. Intestinal dysmicrobism with excessive amounts of different bacterial strains can be found in all patients with IBD. The discovery of Escherichia coli entero-invasive on resection pieces in patients with CD now increases the likelihood of antimicrobial or vaccine-type treatments. Recent studies targeting intestinal immunology and its molecular activation pathways provide new possibilities for therapeutics. In addition to antitumor necrosis factor molecules, which were a breakthrough in IBD, improving mucosal healing and resection-free survival rate, other classes of therapeutic agents come to focus. Leukocyte adhesion inhibitors block the leukocyte homing mechanism and prevent cellular immune response. In addition to anti-integrin antibodies, chemokine receptor antagonists and SMAD7 antisense oligonucleotides have shown encouraging results in clinical trials. Micro-RNAs have demonstrated their role as disease biomarkers but it could also become useful for the treatment of IBD. Moreover, cellular therapy is another therapeutic approach under development, aimed for severe refractory CD. Other experimental treatments include intravenous immunoglobulins, exclusive enteral nutrition, and granulocyte colony-stimulating factors.

Evaluation of tert-butyl isosteres: case studies of physicochemical and pharmacokinetic properties, efficacies, and activities

The tert-butyl group is a common motif in medicinal chemistry. Its incorporation into bioactive compounds is often accompanied by unwanted property modulation, such as increased lipophilicity and decreased metabolic stability. Several alternative substituents are available for the drug discovery process. Herein, physicochemical data of two series of drug analogues of bosentan and vercirnon are documented as part of a comparative study of tert-butyl, pentafluorosulfanyl, trifluoromethyl, bicyclo[1.1.1]pentanyl, and cyclopropyl-trifluoromethyl substituents.

Targeting leukocyte trafficking for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated inflammatory disease of the intestine that includes both Crohn's disease and ulcerative colitis, and afflicts nearly 1 million people throughout North America. As our understanding of IBD pathogenesis grows, several new therapies have been developed that use monoclonal antibodies to specifically target key mediators and biological pathways implicated in IBD immune dysfunction. One important pathway involves leukocyte trafficking and infiltration into the affected intestinal tissues. This review provides a summary of the different therapies that have been developed to inhibit leukocyte trafficking to the inflamed gut, and evaluates the relative safety and efficacy of these novel drugs within the context of existing medical therapies for IBD.