Publications

G protein-coupled receptors (GPCRs) are pivotal in mediating diverse physiological and pathological processes, rendering them promising targets for drug discovery. GPCRs account for about 40% of FDA-approved drugs, representing the most successful drug targets. However, only approximately 15% of the 800 human GPCRs are targeted by market drugs, leaving numerous opportunities for drug discovery among the remaining receptors. Cell expression systems play crucial roles in the GPCR drug discovery field, including novel target identification, structural and functional characterization, potential ligand screening, signal pathway elucidation, and drug safety evaluation. Here, we discuss the principles, applications, and limitations of widely used cell expression systems in GPCR-targeted drug discovery, GPCR function investigation, signal pathway characterization, and pharmacological property studies. We also propose three strategies for constructing genome-wide pan-GPCR cell libraries, which will provide a powerful platform for GPCR ligand screening, and facilitate the study of GPCR mechanisms and drug safety evaluation, ultimately accelerating the process of GPCR-targeted drug discovery.

Beta-hemoglobinopathies are severe genetic diseases caused by mutations affecting the production of the adult β-globin chain. The clinical severity is mitigated by the co-inheritance of mutations that reactivate the production of the fetal β-like γ-globin in adults. However, the epigenetic mechanisms underlying the adult-to-fetal hemoglobin (HbA-to-HbF) switching are still not fully understood. Here, we used epigenome editing technologies to dissect the molecular mechanisms underlying γ- and β-globin gene regulation and to develop novel potential therapeutics for β-hemoglobinopathies. Targeted removal of DNA methylation by dCas9-Tet1 (alone or together with the deposition of histone acetylation by CBP-dCas9) at the fetal promoters led to efficient and durable γ-globin reactivation, demonstrating that DNA methylation is a driver for HbF repression. This strategy, characterized by high specificity and a good safety profile, led to a substantial correction of the pathological phenotype in erythroid cells from patients with sickle cell disease.

To improve ex vivo gene therapy strategies involving hematopoietic stem and progenitor cells (HSPCs), we propose a novel knock-in strategy (named KI-Ep) aiming to achieve transgene regulation of the inserted cassette through the acquisition of naturally occurring epigenetic marks. Based on this hypothesis, we selected CX3CR1 (a myeloid-specific gene presenting a poised histone signature on primitive HSPCs) as safe harbor to generate KI-Ep HSPCs. We demonstrated that, unlike the expression pattern achieved with lentiviral vectors (LVs), the insertion of a constitutive expression cassette into the intron 1 of the CX3CR1 locus (CX3CR1-I) in HSPCs resulted in very low expression levels in the more primitive HSPCs but, crucially, strong expression in HSPC-differentiated populations (especially myeloid cells), both in vitro and in vivo. Furthermore, we showed that the promoter of the expression cassette inserted into CX3CR1-I acquired epigenetic marks associated with poised genes during the HSPC stage. These marks transitioned to activated histone states upon KI-Ep HSPCs differentiation. In summary, here, we introduce the KI-Ep concept which enables the epigenetic modulation of the inserted transgene during the HSPCs stem cell stages and its subsequent activation upon differentiation.

Dipeptidyl peptidase-4 inhibitors (DPP-4i) represent a relatively new class of oral antidiabetic drugs. This study focuses on: (a) identifying favourable and unfavourable fingerprints governing DPP-4 inhibition using fragment-based analysis, (b) validating key fingerprints through HOMO-LUMO gap analysis and electrostatic potential (ESP) maps, and (c) developing AI/ML-driven DPP-4 predictor, an online cheminformatics tool for efficient DPP-4i screening using a trained, validated AI/ML model. The fragment-based QSAR model finds key substructures linked to potent DPP-4 inhibition, including 2-cyanopyrrolidine, 3-amino tetrahydropyran, and difluoro phenyl groups. D0010 (3-aminotetrahydropyran fingerprint G10) is the most reactive, while D0094 (difluorophenyl fingerprint G14) is the most stable, with D0012 and D0013 (2-cyanopyrrolidine fingerprints G1, G5) offering a balance between stability and reactivity. In addition, the d4p_v1 tool (github.com/Amincheminfom/d4p_v1) reliably distinguishes active and inactive DPP-4i using molecular descriptors derived from input SMILES strings. Therefore, this study not only revealed the chemical space of DPP-4i but also opened up a horizon in developing novel potent DPP-4i for the management of type 2 diabetes mellitus (T2DM)

The development of extracellular vesicles (EVs) therapies has revolutionized personalized medicine, opening up new possibilities for treatment. EVs have emerged as a promising therapeutic tool within this field due to their crucial role in intercellular communication across various cell types and organisms. This systematic review aims to evaluate the therapeutic potential of oral mesenchymal stem cell (MSC)-derived EVs for bone regeneration, specifically focusing on findings from preclinical models. Sixteen articles meeting the inclusion criteria were selected following document analysis. The biological effects of oral MSC-derived EVs predominantly involve the upregulation of proteins associated with angiogenesis, and inflammation resolution, alongside the downregulation of proinflammatory cytokines. Moreover, these therapeutic agents have been found to contain a significant quantity of different molecules (proteins, lipids, DNA, microRNAs, etc) further contributing to their modulatory potential. The findings from this systematic review underscore that oral MSC-derived EVs, irrespective of their specific population, have the ability to enhance the osteogenic repair response in maxillary bone or periodontal defects. In summary, this systematic review highlights the promising potential of oral MSC-derived EVs for bone regeneration based on evidence from preclinical models. The comprehensive assessment of their biological effects and the presence of microRNAs underscores their therapeutic significance. These findings support the utilization of oral MSC-derived EVs in enhancing the osteogenic repair response in various maxillary bone or periodontal defects, providing insights into the mechanisms involved and potential therapeutic applications in the field of personalized medicine.