In-silico guided identification and in-vitro studies of potential FFAR4 agonists for type 2 diabetes mellitus therapy

Abstract

Background: The activation of free fatty acid receptor 4 (FFAR4) enhances insulin sensitivity and glucose uptake while mitigating inflammation. It is a promising therapeutic approach for managing type 2 diabetes mellitus (T2DM).

Research design and methods: Structure and Ligand-based screening approaches were employed to evaluate 1.1 million molecules for FFAR4 agonistic activity. Eight promising candidates were selected based on their binding affinity, non-bonded interactions, and pharmacokinetic properties and subjected to 500 ns molecular dynamics simulations (MDS). The therapeutic efficacy of compounds was assessed through in vitro assays, including cell viability tests, glucose uptake analysis, and gene expression profiling.

Results: The analysis revealed several residues (VAL98, ARG99, ARG183, ARG22, ARG24, GLU43, and TRP305) that are essential for biological activity. Insights into the mechanistic contribution of amino acid residues located in the extracellular and intracellular loops of FFAR4 to ligand binding were obtained through MDS analysis. The binding energy values indicate a stronger binding affinity between the FFAR4 and hit molecules. In vitro experiments on selected compounds (Comp35, CompN1, CompN2, and diosmetin) confirmed their potential effects on insulin-stimulated glucose uptake, IR, inflammation, and diabetic pathways.

Conclusions: Comp35, diosmetin, CompN1, and CompN2 were found to be potential hit agonists and can be developed for therapy.

Keywords: Free fatty acid receptor 4; glucose uptake; homeostasis; insulin resistance; machine learning; type 2 diabetes; virtual screening.