d-Peptides as inhibitors of PR3-membrane interactions

Construction of the Gal-NH2/mulberry leaf polysaccharides-lysozyme/luteolin nanoparticles and the amelioration effects on lipid accumulation

Luteolin is a kind of natural flavonoid with great potential for lipid accumulation intervention. However, the poor water solubility and non-targeted release greatly diminish its efficiency. In this study, 4-aminophenyl β-D-galactopyranoside (Gal-NH2)/mulberry leaf polysaccharides- lysozyme/luteolin nanoparticles (Gal-MPL/Lut) were fabricated via amide reaction, self-assembly process and electrostatic interaction. The nanoparticles could hepatic-target of Lut and enhance action on liver tissue by specific recognition of asialoglycoprotein receptor (ASGPR). Physicochemical characterization of the nanoparticles showed a spherical shape with a uniform particle size distribution (77.8 ± 2.6 nm) with a polydispersity index (PDI) of 0.22 ± 0.06. Subsequently, in HepG2 cells model, administration with hepatic-targeted Gal-MPL/Lut nanoparticles promoted the cellular uptake of Lut, and regulated lipid metabolism manifested by remarkably inhibiting total cholesterol (TC) and triglyceride (TG) expression levels through the modulation of PI3K/SIRT-1/FAS/CEBP-α signaling pathway. This study provides a promising strategy for a highly hepatic-targeted therapy to ameliorate lipid accumulation using natural medicines facilitated by nano-technology.

Development of the Antithrombotic Peptide LEKNSTY Targeting the Collagen Surface: II. Improvement of Plasma Stability

The development of antithrombotic peptides targeting collagen was proven effective, and an effective antithrombotic peptide LEKNSTY was obtained in part I. However, the plasma stability of LEKNSTY was found to be not good enough. In this part, the LEKNSTY was further optimized for improvement in plasma stability by substitution using d-amino acid residues. Two novel antithrombotic peptides LekNStY and lEKnsTy were designed, where lowercase letters represent d-amino acid residues. Improvements in plasma stability of both LekNStY and lEKnsTy were experimentally confirmed. Moreover, good binding of these antithrombotic peptides on the collagen surface was confirmed by molecular dynamics simulation and experimental validation. For example, a K_d of only 0.75 ± 0.10 μM was observed for lEKnsTy. Moreover, LekNStY and lEKnsTy were found to inhibit platelet adhesion on the collagen surface more effectively than LEKNSTY, and the IC₅₀ of lEKnsTy was only 2/5 of that of LEKNSTY. These results confirmed the successful design of LekNStY and lEKnsTy that had good plasma stability and could effectively inhibit arterial thrombosis, which would be helpful for the research into interfaces involved in thrombus formation and the development of antithrombotic nanomedicine.

Proteinase 3; a potential target in chronic obstructive pulmonary disease and other chronic inflammatory diseases

Chronic Obstructive Pulmonary Disease (COPD) is a common, multifactorial lung disease which results in significant impairment of patients' health and a large impact on society and health care burden. It is believed to be the result of prolonged, destructive neutrophilic inflammation which results in progressive damage to lung structures. During this process, large quantities of neutrophil serine proteinases (NSPs) are released which initiate the damage and contribute towards driving a persistent inflammatory state.Neutrophil elastase has long been considered the key NSP involved in the pathophysiology of COPD. However, in recent years, a significant role for Proteinase 3 (PR3) in disease development has emerged, both in COPD and other chronic inflammatory conditions. Therefore, there is a need to investigate the importance of PR3 in disease development and hence its potential as a therapeutic target. Research into PR3 has largely been confined to its role as an autoantigen, but PR3 is involved in triggering inflammatory pathways, disrupting cellular signalling, degrading key structural proteins, and pathogen response.This review summarises what is presently known about PR3, explores its involvement particularly in the development of COPD, and indicates areas requiring further investigation.