Open Source Repurposing Reveals Broad-Spectrum Antiviral Activity of Diphenylureas.

The pandemic threat from newly emerging viral diseases constitutes a major unsolved issue for global health. Antiviral therapy can play an important role in treating and preventing the spread of unprecedented viral infections. A repository of compounds exhibiting broad-spectrum antiviral activity against a series of different viral families would be an invaluable asset to be prepared for future pandemic threats.

Merck Open Global Health Library in vitro screening against Schistosoma mansoni identified two new substances with antischistosomal activities for further development.

Background: Schistosomiasis, which is caused by the parasite Schistosoma mansoni as well as other species of the trematode genus Schistosoma, leads to chronic inflammation and finally to liver fibrosis. If untreated, the disease can cause life-threatening complications. The current treatment of schistosomiasis relies on a single drug, praziquantel (PZQ).

Translational pharmacokinetic and pharmacodynamic modelling of the anti-ADAMTS-5 NANOBODY (M6495) using the neo-epitope ARGS as a biomarker.

M6495 is a first-in-class NANOBODY molecule and an inhibitor of ADAMTS-5, with the potential to be a disease modifying osteoarthritis drug. In order to investigate the PK/PD (pharmacokinetic and pharmacodynamic) properties of M6495, a single dose study was performed in cynomolgus monkeys with doses up to 6 mg/kg, with the goal of understanding the PK/PD properties of M6495. The neo-epitope ARGS (Alanine-Arginine-Glycine-Serine) generated by cleavage of aggrecan by ADAMTS-5 was used as a target-engagement biomarker.

Repurposing the Open Global Health Library for the discovery of novel Mpro destabilizers with scope as broad-spectrum antivirals.

The SARS coronavirus 2 (SARS-CoV-2) epidemic remains globally active. The emergence of new variants of interest and variants of concern (VoCs), which are potentially more vaccine-resistant and less sensitive to existing treatments, is evident due to their high prevalence. The prospective spread of such variants and other coronaviruses with epidemic potential demands preparedness that can be met by developing fast-track workflows to find new candidates that target viral proteins with a clear and phenotype.

Target 2035 - an update on private sector contributions.

Target 2035, an international federation of biomedical scientists from the public and private sectors, is leveraging 'open' principles to develop a pharmacological tool for every human protein. These tools are important reagents for scientists studying human health and disease and will facilitate the development of new medicines. It is therefore not surprising that pharmaceutical companies are joining Target 2035, contributing both knowledge and reagents to study novel proteins.

A serological type II collagen neoepitope biomarker reflects cartilage breakdown in patients with osteoarthritis.

Objectives: There is an unmet medical need for biomarkers in OA which can be applied in clinical drug development trials. The present study describes the development of a specific and robust assay measuring type II collagen degradation (T2CM) and discusses its potential as a noninvasive translational biomarker.

Methods: A type II collagen specific neoepitope (T2CM) was identified by mass spectrometry and monoclonal antibodies were raised towards the epitope, employed in a chemiluminescence immunoassay.

Early detection of osteoarthritis in the rat with an antibody specific to type II collagen modified by reactive oxygen species.

Background: Osteoarthritis (OA) is a disease of the whole joint, with articular cartilage breakdown as a major characteristic. Inflammatory mediators, proteases, and oxidants produced by chondrocytes are known to be responsible for driving cartilage degradation. Nevertheless, the early pathogenic events are still unclear.

The Anti-ADAMTS-5 Nanobody M6495 Protects Cartilage Degradation Ex Vivo.

Osteoarthritis (OA) is associated with cartilage breakdown, brought about by ADAMTS-5 mediated aggrecan degradation followed by MMP-derived aggrecan and type II collagen degradation. We investigated a novel anti-ADAMTS-5 inhibiting Nanobody (M6495) on cartilage turnover ex vivo. Bovine cartilage (BEX, = 4), human osteoarthritic - (HEX, = 8) and healthy-cartilage (hHEX, = 1) explants and bovine synovium and cartilage were cultured up to 21 days in medium alone (/), with pro-inflammatory cytokines (oncostatin M (10 ng/mL) + TNFα (20 ng/mL) (O + T), IL-1α (10 ng/mL) or oncostatin M (50 ng/mL) + IL-1β (10 ng/mL)) with or without M6495 (1000-0.

BMPR1A is necessary for chondrogenesis and osteogenesis, whereas BMPR1B prevents hypertrophic differentiation.

BMP2 stimulates bone formation and signals preferably through BMP receptor (BMPR) 1A, whereas GDF5 is a cartilage inducer and signals preferably through BMPR1B. Consequently, BMPR1A and BMPR1B are believed to be involved in bone and cartilage formation, respectively. However, their function is not yet fully clarified.

The GDF-5 mutant M1673 exerts robust anabolic and anti-catabolic effects in chondrocytes.

The growth and differentiation factor 5 (GDF-5) is known to play a key role in cartilage morphogenesis and homeostasis, and a single-nucleotide polymorphism in its promoter sequence was found to be associated with osteoarthritis (OA). In addition, GDF-5 was shown to promote extracellular matrix (ECM) production in healthy chondrocytes, to stimulate chondrogenesis of mesenchymal stem cells (MSCs) and to protect against OA progression in vivo. Therefore, GDF-5 appears to be a promising treatment for osteoarthritis.

Importance of Osmolarity and Oxygen Tension for Cartilage Tissue Engineering.

For cartilage repair or evaluation of new therapeutic approaches , the generation of functional cartilage tissue is of crucial importance and can only be achieved if the phenotype of the chondrocytes is preserved. Three-dimensional (3D) cell culture is broadly used for this purpose. However, adapting culture parameters like the oxygen tension or the osmolarity to their physiological values is often omitted.

Increasing the Medium Osmolarity Reduces the Inflammatory Status of Human OA Chondrocytes and Increases Their Responsiveness to GDF-5.

The environment surrounding chondrocytes changes drastically in osteoarthritis (OA). For instance, the osmolarity in cartilage (ranging from 350 to 460 mOsm in healthy tissue) decreases during the progression of OA, reaching 270 mOsm. The objective of this study was to evaluate how osmolarity influences human OA chondrocytes.

Effects of Sprifermin, IGF1, IGF2, BMP7, or CNP on Bovine Chondrocytes in Monolayer and 3D Culture.

One possible approach to treat osteoarthritis (OA) is to counteract cartilage degeneration with anabolic compounds that stimulate chondrocyte proliferation and/or extracellular matrix (ECM) production. Several molecules including sprifermin (recombinant human fibroblast growth factor [FGF18]), insulin-like growth factor-1 [IGF1] and -2 [IGF2], C-type natriuretic peptide [CNP], and bone metamorphic protein 7 [BMP7] have been shown to have these characteristics both in vitro and in vivo. However, it is not known how these molecules compare each other regarding their effect on phenotype and stimulation of ECM production in primary chondrocytes.

Structure-based optimization of non-peptidic Cathepsin D inhibitors.

We discovered a novel series of non-peptidic acylguanidine inhibitors of Cathepsin D as target for osteoarthritis. The initial HTS-hits were optimized by structure-based design using CatD X-ray structures resulting in single digit nanomolar potency in the biochemical CatD assay. However, the most potent analogues showed only micromolar activities in an ex vivo glycosaminoglycan (GAG) release assay in bovine cartilage together with low cellular permeability and suboptimal microsomal stability.

Receptor fingerprinting the circling ci2 rat mutant: insights into brain asymmetry and motor control.

Circling behaviour of the ci2 rat mutant, a model for hyperkinetic movement disorders, is associated with an abnormal asymmetry in striatal dopaminergic activity. Since it is more likely that imbalances in several neurotransmitter systems result in the cascade of neurochemical disturbances underlying disorders involving motor dysfunctions, we measured the densities of 12 neurotransmitter receptors in the basal ganglia and vestibular nuclei of adult circling mutants (ci2/ci2), non-circling littermates (ci2/+) and controls from the background strain (LEW/Ztm). In controls, the left caudate putamen (CPu) contains lower kainate and the left globus pallidus higher AMPA densities than their right counterparts.

Comparative analysis of anxiety-like behaviors and sensorimotor functions in two rat mutants, ci2 and ci3, with lateralized rotational behavior.

There is increasing evidence that developmental anomalies of cerebral asymmetry are involved in the etiology of psychiatric disorders, including schizophrenia, depression and anxiety. Thus, rodents with abnormal cerebral lateralization are interesting tools to study the association between such anomalies and behavioral dysfunction. The most studied indicator of cerebral asymmetry in the rat is that of circling or rotational behavior.

Auditory and vestibular defects and behavioral alterations after neonatal administration of streptomycin to Lewis rats: Similarities and differences to the circling (ci2/ci2) Lewis rat mutant.

The clinical usefulness of aminoglycoside antibiotics is limited by their ototoxicity. In rodents, damage to the inner ear is often associated with rotational behavior and locomotor hyperactivity reminiscent of such behaviors resulting from an imbalance of forebrain dopamine systems. Based on previous observations in the circling (ci2/ci2) Lewis (LEW) rat mutant, a spontaneous mutation leading to hair cell loss, deafness, impairment of vestibular functions, lateralized circling, hyperactivity and alterations in the nigrostriatal dopamine system, we have recently hypothesized that vestibular defects during postnatal development, independent of whether induced or inherited, lead to secondary changes in the dopaminergic system within the basal ganglia, which would be a likely explanation for the typical behavioral phenotype seen in such models.

Marked differences in response to dopamine receptor antagonism in two rat mutants, ci2 and ci3, with lateralized rotational behavior.

We have recently described two rat mutants, ci2 and ci3, in which abnormal lateralized rotational behavior and locomotor hyperactivity occur either spontaneously or in response to external stimuli, such as new environment. While cochlear and vestibular defects are found in ci2 rats, ci3 rats do not exhibit any inner ear abnormalities. Both mutants show abnormal lateralities in striatal dopamine and in the density of dopaminergic neurons in substantia nigra or ventral tegmental area, which may be involved in the behavioral phenotype of these rats.