Development and Characterization of a High-Affinity Selective Galectin-3 Mouse Tool Compound in Mouse Models of Cancer.

The interest in galectin-3 as a drug target in the cancer and fibrosis space has grown during the past few years with several new classes of compounds being developed. The first orally available galectin-3 inhibitor, (h-galectin-3 K = 0.025 μM), is currently in phase 2 clinical trials.

Galectin-1 Induces the Production of Immune-Suppressive Cytokines in Human and Mouse T Cells.

Galectin-1 is implicated in several pro-tumourigenic mechanisms and is considered immune-suppressive. The pharmacological inhibition of galectin-1 may be beneficial in cancers in which galectin-1 is overexpressed and driving cancer progression. This study aimed to further characterise the immunosuppressive cytokines influenced by galectin-1 in in vitro immune cell cultures and an in vivo inflammatory model using a recently discovered selective inhibitor of galectin-1, GB1908.

Sulfonamide-derivatized galactosides selectively target an unexplored binding site in the galectin-9N-terminal domain.

Four directional and positional variants of sulfonamide-derivatized galactopyranosides were synthesized and evaluated against human galectin-1, -3, -4C (C-terminal), -7, -8N (N-terminal), -8C (C-terminal), -9N (N-terminal), and -9C (C-terminal), which revealed that one of the sulfonamide positions and directionalities (methyl 3-{4-[2-(phenylsulfonylamino)-phenyl]-triazolyl}-3-deoxy-α-d-galactopyranosides) bound with 6-15 fold higher affinity than the corresponding phenyltriazole (lacking the phenylsulfonamide moiety) for galectin-9N. Molecular dynamic simulations suggested that inhibitor adopted a conformation that is complementary to the galectin-9N binding site and where the sulfonamide moiety protrudes into an unexplored and non-conserved binding site perpendicular to and below the A-B subsite to interact with a His61 NH proton. This resulted in the discovery of galectin-9N inhibitors with unprecedented selectivity over other galectins, thus constituting valuable tools for studies of the biological functions of galectin-9.

Effect of GB1107, a novel galectin-3 inhibitor on pro-fibrotic signalling in the liver.

Background And Purpose: Galectin-3 (Gal-3) is a pro-fibrotic β-galactoside binding lectin highly expressed in fibrotic liver and implicated in hepatic fibrosis. GB1107 is a novel orally active Gal-3 small molecule inhibitor that has high affinity for Gal-3 >1000-fold selectively over other galectins. The aim of this study was to characterise GB1107 and galectin-3 in vitro and in vivo in the context of fibrosis signalling and liver disease.

Single‑Dose Pharmacokinetics and Safety of the Oral Galectin‑3 Inhibitor, Selvigaltin (GB1211), in Participants with Hepatic Impairment.

Background And Objectives: Selvigaltin (GB1211), an orally available small molecule galectin-3 inhibitor developed as a treatment for liver fibrosis and cirrhosis, was evaluated to assess the effect of hepatic impairment on its pharmacokinetics and safety to address regulatory requirements.

Methods: GULLIVER-2 was a Phase Ib/IIa three-part study. Parts 1 and 3 had single-dose, open-label designs assessing pharmacokinetics (plasma [total and unbound] and urine), safety, and tolerability of 100 mg oral selvigaltin in participants with moderate (Child-Pugh B, Part 1) or severe (Child-Pugh C, Part 3) hepatic impairment, compared with healthy-matched participants (n = 6 each).

Relative bioavailability and food effect of the galectin-3 inhibitor selvigaltin (GB1211) administered as a tablet in healthy participants (GALBA-1).

Purpose: Overexpression of galectin-3, a β-galactoside-binding lectin, is associated with fibrotic diseases and cancer. Selvigaltin is an oral galectin-3 inhibitor, previously administered as a 50 mg capsule. This study aimed to evaluate the relative bioavailability and food effect of selvigaltin as a 100 mg tablet in healthy volunteers.

The galectin-3 inhibitor selvigaltin reduces liver inflammation and fibrosis in a high fat diet rabbit model of metabolic-associated steatohepatitis.

Introduction: Galectin-3 is a pro-fibrotic β-galactoside binding lectin highly expressed in fibrotic liver and implicated in hepatic fibrosis. Selvigaltin (previously known as GB1211) is a novel orally active galectin-3 small molecule inhibitor that has high affinity for galectin-3 (human K = 25 nM; rabbit K = 12 nM) and high oral bioavailability in rabbits and man. In this study the efficacy of selvigaltin was investigated in a high fat diet (HFD) rabbit model of metabolic-associated steatohepatitis (MASH).

Determining the Affinity and Kinetics of Small Molecule Inhibitors of Galectin-1 Using Surface Plasmon Resonance.

The beta-galactoside-binding mammalian lectin galectin-1 can bind, via its carbohydrate recognition domain (CRD), to various cell surface glycoproteins and has been implicated in a range of cancers. As a consequence of binding to sugar residues on cell surface receptors, it has been shown to have a pleiotropic effect across many cell types and mechanisms, resulting in immune system modulation and cancer progression. As a result, it has started to become a therapeutic target for both small and large molecules.

Myocardin related transcription factor and galectin-3 drive lipid accumulation in human blood vessels.

Objective: Diabetes and hypertension are important risk factors for vascular disease, including atherosclerosis. A driving factor in this process is lipid accumulation in smooth muscle cells of the vascular wall. The glucose- and mechano-sensitive transcriptional coactivator, myocardin-related transcription factor A (MRTF-A/MKL1) can promote lipid accumulation in cultured human smooth muscle cells and contribute to the formation of smooth muscle-derived foam cells.

Discovery of the Selective and Orally Available Galectin-1 Inhibitor GB1908 as a Potential Treatment for Lung Cancer.

We have previously described a new series of selective and orally available galectin-1 inhibitors resulting in the thiazole-containing glycomimetic GB1490. Here, we show that the introduction of polar substituents to the thiazole ring results in galectin-1-specific compounds with low nM affinities. X-ray structural analysis of a new ligand-galectin-1 complex shows changes in the binding mode and ligand-protein hydrogen bond interactions compared to the GB1490-galectin-1 complex.

Defining the mechanism of galectin-3-mediated TGF-β1 activation and its role in lung fibrosis.

Integrin-mediated activation of the profibrotic mediator transforming growth factor-β1 (TGF-β1), plays a critical role in idiopathic pulmonary fibrosis (IPF) pathogenesis. Galectin-3 is believed to contribute to the pathological wound healing seen in IPF, although its mechanism of action is not precisely defined. We hypothesized that galectin-3 potentiates TGF-β1 activation and/or signaling in the lung to promote fibrogenesis.

Interplay of halogen bonding and solvation in protein-ligand binding.

Halogen bonding is increasingly utilized in efforts to achieve high affinity and selectivity of molecules designed to bind proteins, making it paramount to understand the relationship between structure, dynamics, and thermodynamic driving forces. We present a detailed analysis addressing this problem using a series of protein-ligand complexes involving single halogen substitutions - F, Cl, Br, and I - and nearly identical structures. Isothermal titration calorimetry reveals an increasingly favorable binding enthalpy from F to I that correlates with the halogen size and σ-hole electropositive character, but is partially counteracted by unfavorable entropy, which is constant from F to Cl and Br, but worse for I.

Anti-Angiogenic and Anti-Scarring Dual Effect of Galectin-3 Inhibition in Mouse Models of Corneal Wound Healing.

Corneal scarring is the third leading cause of global blindness. Neovascularization of ocular tissues is a major predisposing factor in scar development. Although corneal transplantation is effective in restoring vision, some patients are at high risk for graft rejection due to the presence of blood vessels in the injured cornea.

Discovery of Selective and Orally Available Galectin-1 Inhibitors.

A new series of orally available α-d-galactopyranosides with high affinity and specificity toward galectin-1 have been discovered. High affinity and specificity were achieved by changing six-membered aryl-triazolyl substituents in a series of recently published galectin-3-selective α-d-thiogalactosides (e.g.

Resistance to anti-PD-1/anti-PD-L1: galectin-3 inhibition with GB1211 reverses galectin-3-induced blockade of pembrolizumab and atezolizumab binding to PD-1/PD-L1.

Background: Galectin-3 (Gal-3) is a β-galactoside-binding lectin that is highly expressed within the tumor microenvironment of aggressive cancers and has been suggested to predict a poor response to immune checkpoint therapy with the anti-PD-1 monoclonal antibody pembrolizumab. We aimed to assess if the effect of Gal-3 was a result of direct interaction with the immune checkpoint receptor.

Methods: The ability of Gal-3 to interact with the PD-1/PD-L1 complex in the absence and presence of blocking antibodies was assessed in biochemical and cellular assays as well as in an syngeneic mouse cancer model.

Evaluating the affinity and kinetics of small molecule glycomimetics for human and mouse galectin-3 using surface plasmon resonance.

Galectin-3 is a beta-galactoside-binding mammalian lectin that is one of a 15-member galectin family that can bind several cell surface glycoproteins via its carbohydrate recognition domain (CRD). As a result, it can influence a range of cellular processes including cell activation, adhesion and apoptosis. Galectin-3 has been implicated in various diseases, including fibrotic disorders and cancer, and is now being therapeutically targeted by both small and large molecules.

Safety and pharmacokinetics of GB1211, an oral galectin-3 inhibitor: a single- and multiple-dose first-in-human study in healthy participants.

Purpose: Galectin-3, a β-galactoside-binding lectin, plays a key role in several cellular pathways involved in chronic inflammation, heart disease and cancer. GB1211 is an orally bioavailable galectin-3 inhibitor, developed to be systemically active. We report safety and pharmacokinetics (PK) of GB1211 in healthy participants.

N-BAR and F-BAR proteins-endophilin-A3 and PSTPIP1-control clathrin-independent endocytosis of L1CAM.

Recent advances in the field demonstrate the high diversity and complexity of endocytic pathways. In the current study, we focus on the endocytosis of L1CAM. This glycoprotein plays a major role in the development of the nervous system, and is involved in cancer development and is associated with metastases and poor prognosis.

Galectin-8 Downmodulates TLR4 Activation and Impairs Bacterial Clearance in a Mouse Model of Pseudomonas aeruginosa Keratitis.

Pseudomonas aeruginosa provokes a painful, sight-threatening corneal infection. It progresses rapidly and is difficult to treat. In this study, using a mouse model of P.

Discovery and Optimization of the First Highly Effective and Orally Available Galectin-3 Inhibitors for Treatment of Fibrotic Disease.

Galectin-3 is a carbohydrate-binding protein central to regulating mechanisms of diseases such as fibrosis, cancer, metabolic, inflammatory, and heart disease. We recently found a high affinity (nM) thiodigalactoside GB0139 which currently is in clinical development (PhIIb) as an inhaled treatment of idiopathic pulmonary fibrosis. To enable treatment of systemically galectin-3 driven disease, we here present the first series of selective galectin-3 inhibitors combining high affinity (nM) with oral bioavailability.

Benzimidazole-galactosides bind selectively to the Galectin-8 N-Terminal domain: Structure-based design and optimisation.

We have obtained the X-ray crystal structure of the galectin-8 N-terminal domain (galectin-8N) with a previously reported quinoline-galactoside ligand at a resolution of 1.6 Å. Based on this X-ray structure, a collection of galactosides derivatised at O3 with triazole, benzimidazole, benzothiazole, and benzoxazole moieties were designed and synthesised.

Crosstalk between WNT and STAT3 is mediated by galectin-3 in tumor progression.

Background: Aberrant activation of the WNT/β-catenin and STAT3 signaling pathways plays a critical role in cancer progression. However, direct targeting of these pathways as an anti-cancer therapeutic approach needs to be reconsidered due to its serious side effects. Here, we demonstrate that overexpression of WNT induces STAT3 activation in a galectin-3-dependent manner.

Target inhibition of galectin-3 by inhaled TD139 in patients with idiopathic pulmonary fibrosis.

Galectin (Gal)-3 is a profibrotic β-galactoside-binding lectin that plays a key role in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and IPF exacerbations. TD139 is a novel and potent small-molecule inhibitor of Gal-3.A randomised, double-blind, multicentre, placebo-controlled, phase 1/2a study was conducted to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of inhaled TD139 in 36 healthy subjects and 24 patients with IPF.

: F-Radiolabeled Glycomimetics Allow Insights into the Pharmacological Fate of Galectin-3 Inhibitors.

Glycomimetic drugs have attracted increasing interest as unique targeting vectors or surrogates for endogenous biomolecules. However, it is generally difficult to determine the pharmacokinetic profile of these compounds. In this work, two galectin-3 inhibitors were radiolabeled with fluorine-18 and used as surrogate PET tracers of TD139 and GB1107.

3-Substituted 1-Naphthamidomethyl-C-galactosyls Interact with Two Unique Sub-sites for High-Affinity and High-Selectivity Inhibition of Galectin-3.

The galectins are a family of galactose-binding proteins playing key roles in inflammatory processes and cancer. However, they are structurally very closely related, and discovery of highly selective inhibitors is challenging. In this work, we report the design of novel inhibitors binding to a subsite unique to galectin-3, which confers both high selectivity and affinity towards galectin-3.