Search

G protein-coupled receptors (GPCRs), as the largest family of membrane receptors, actively modulate plasma membrane and endosomal signalling. Importantly, GPCRs are naturally nanosized, and spontaneously formed nanoaggregates of GPCRs (natural nano-GPCRs) may enhance GPCR-related signalling and functions. Although GPCRs are the molecular targets of the majority of marketed drugs, the poor pharmacokinetics and physicochemical properties of GPCR ligands greatly limit their clinical applicability. Nanotechnology, as versatile techniques, can encapsulate GPCR ligands to assemble synthetic nano-GPCRs to overcome their obstacles, robustly elevating drug efficacy and safety. Moreover, endosomal delivery of GPCR ligands by nanoparticles can precisely initiate sustained endosomal signal transduction, while nanotechnology has been widely utilized for isolation, diagnosis, and detection of GPCRs. In turn, due to overexpression of GPCRs on the surface of various types of cells, GPCR ligands can endow nanoparticles with active targeting capacity for specific cells via ligand-receptor binding and mediate receptor-dependent endocytosis of nanoparticles. This significantly enhances the potency of nanoparticle delivery systems. Therefore, emerging evidence has revealed the interplay between GPCRs and nanoparticles, although investigations into their relationship have been inadequate. This review aims to summarize the interaction between GPCRs and nanotechnology for understanding their mutual influences and utilizing their interplay for biomedical applications. It will provide a fundamental platform for developing powerful and safe GPCR-targeted drugs and nanoparticle systems. GPCRs as molecular targets for the majority of marketed drugs are naturally nanosized, and even spontaneously form nano aggregations (nano-GPCRs). Nanotechnology has also been applied to construct synthetic nano-GPCRs or detect GPCRs, while endosomal delivery of GPCR ligands by nanoparticles can magnify endosomal signalling. Meanwhile, molecular engineering of nanoparticles with GPCRs or their ligands can modulate membrane binding and endocytosis, powerfully improving the efficacy of nanoparticle system. However, there are rare summaries on the interaction between GPCRs and nanoparticles. This review will not only provide a versatile platform for utilizing nanoparticles to modulate or detect GPCRs, but also facilitate better understanding of the designated value of GPCRs for molecular engineering of biomaterials with GPCRs in therapeutical application. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The interleukin-1 receptor antagonist (IL-1Ra), having the potential of treating cancers, has been used for treating rheumatoid arthritis in clinic. To improve its therapeutic efficacy and patient compliance, IL-1Ra was often needed to prepare a long efficacy formulation using all kinds of method for protein stabilization. In this study, we reported a novel freezing-induced PEG water solution phase/dextran water solution phase separation method to prepare the IL-1Ra-loaded dextran microparticles to address stability of IL-1Ra in preparation process for all kinds of formulation, namely: first IL-1Ra was dissolved in water together with dextran and polyethylene glycol, and then by a freezing process during which dextran is separated out as the dispersed phase with IL-1Ra partitioned in dextran microparticles preferentially. The frozen sample was then lyophilized to powder and washed with dichloromethane to remove the PEG continuous phase. Once IL-Ra was loaded in the dextran microparticles, 1–5μm in diameter, the dextran microparticles gained resistance to oil/water interfaces without IL-Ra aggregation and activity loss. The bioactivity from dextran microparticles in vitro is preserved highly (above 98%), while bioactivity from IL-1Ra-loaded dextran microparticles using the control method of water-in-oil-in-water (W/O/W) method is only 70.5% by inhibiting melanoma B16 cell proliferation. The dextran microparticles may be used further to prepare different formulations according to clinic needs. [Copyright &y& Elsevier]

Osimertinib, as the third-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs), is a first-line molecularly targeted drug for non-small cell lung cancer (NSCLC). However, the emergence of therapeutic resistance to osimertinib markedly impairs its efficiency and efficacy, leading to the failure of clinical applications. Novel molecular targets and drugs are urgently needed for reversing osimertinib resistance in NSCLC. Protease-activated receptor 2 (PAR2) that belongs to a subfamily of G protein-coupled receptors can stimulate the transactivation of EGFR to regulate multiple cellular signalling, actively participating in tumour progression. This study firstly discovered that PAR2 expression was notably enhanced when NSCLC cells became resistant to osimertinib. A PAR2 inhibitor facilitated osimertinib to attenuate EGFR transactivation, ERK phosphorylation, EMT and PD-L1 expression which were associated to osimertinib resistance. The combination of the PAR2 inhibitor and osimertinib also notably blocked cell viability, migration, 3D sphere formation and in vivo tumour growth whereas osimertinib itself lost such inhibitory effects in osimertinib-resistant NSCLC cells. Importantly, this reversal effect of PAR2 blockade was uncovered to depend on ERK-mediated EMT and PD-L1, since inhibition of β-arrestin or ERK, which could be modulated by PAR2, sensitized osimertinib to prevent EMT, PD-L1 expression and consequently overcame osimertinib resistance. Thus, this study demonstrated that PAR2 antagonism could limit ERK-mediated EMT and immune checkpoints, consequently attenuating EGFR transactivation and reactivate osimertinib. It suggested that PAR2 may be a novel drug target for osimertinib resistance, and PAR2 inhibition may be a promising strategy candidate for reversing EGFR-TKI resistance in NSCLC. • Targeting PAR2 overcame osimertinib resistance in NSCLCs. • PAR2 inhibition reactivated osimertinib to attenuate in vivo NSCLC tumour growth. • PAR2 modulated osimertinib resistance via ERK-mediated EMT and PD-L1. [ABSTRACT FROM AUTHOR]

A chemical investigation of the extract of the marine-sponge-associated fungus P. colombiensis resulted in the isolation of eight chlorinated benzophenone derivatives, named, pestalone (1), pestalachlorides A-C, E, and F (2 - 6), pestalalactone (7), and pestalalactone atropisomer (8). The structures of these compounds were identified by spectroscopic analysis (MS, 1D/2D NMR) and comparison with the previously reported data. Compounds (1 – 8) were isolated from this species for the first time. Moreover, compounds (1 – 8) had not been reported from any other genus , and the chemotaxonomic signifcance of eight chlorinated benzophenone derivatives (1 – 8) was also discussed. • Chlorinated benzophenone derivatives (1-8) were isolated from the marine-sponge-associated fungus pestalotiopsis colombiensis. Compounds (1 – 8) were isolated from this species for the first time. Chlorinated benzophenone derivatives (1 – 8) could be used as chemotaxonomic markers for the genus of pestalotiopsis. [ABSTRACT FROM AUTHOR]