Editorial [Hot Topic: Therapeutic Potential of Peptide Motifs - Part II (Executive Editor: Jean-Claude Herve)]

The production of new molecular entities endowed with salutary medicinal properties is a formidable challenge; synthetic molecules that can bind with high sequence specificity to a chosen target in a protein or gene sequence are of major interest in medicinal and biotechnological contexts. The general awareness of the importance of peptides in physiology and pathophysiology has markedly increased over the last few years. With progresses in the analysis of whole genomes, the knowledge base in gene sequence and expression data useful for protein and peptide analysis has drastically increased. The medical need for relevant biomarkers is enormous. This is particularly true for the many types of cancers, but also for other diseases, e.g. type 2 diabetes or cardiac diseases, which also lack adequate diagnostic markers with high specificity and sensitivity. Imaging technologies for early detection of diseases, proteomic and peptidomic multiplex techniques have markedly evolved in recent years. Peptides can indeed be regarded as ideal agents (as “magic bullets”) for diagnostic and therapeutic applications because of their fast clearance, rapid tissue penetration, and low antigenicity, and also of their easy production, allowing innumerable biological applications. They can easily be engineered to improve their biological activities as well as their stability and their efficient delivery to specific targets. This second themed issue of Current Pharmaceutical Design, for which I have the honour to be Executive Guest Editor, addresses topical issues to some of these potential utilizations of peptide motifs for a variety of genetic and acquired diseases. A collection of biological processes protect both animal and plant kingdoms from pathogens and tumour cells, detecting a wide variety of agents (from viruses to parasitic worms), distinguishing them from the organism's own healthy cells and tissues. The protective immunity against pathogenic infection can be divided into innate and adaptive immunities, respectively representing the first defence barrier in the host and the second line defence including T (cellular) and B (humoral) cell mediated responses. Antimicrobial peptides (AMPs) are an essential part of innate immunity that evolved in living organisms over 2.6 billion years to combat microbial challenge, and their fundamental biological role in vivo has been proposed to be the elimination of pathogenic microorganisms, including Gram-positive and -negative bacteria, fungi, and viruses. Gill Diamond, Nicholas Beckloff, Aaron Weinberg and Kevin O. Kisich [1] summarise AMP structure and function and overview the varied activities of AMPs in mammals, which may help to understand their roles in innate host defence. AMPs found in the skin, beside their endogenous antibiotic ability, play important roles in normal skin function and in various skin conditions, overviewed by Francois Niyonsaba, Isao Nagaoka, Hideoki Ogawa and Ko Okumura [2], who also explore the future of AMPs as potential therapeutics for various infection- and/or inflammatory-related skin diseases. Growth factors (GFs), extracellular signalling polypeptides capable of stimulating cellular growth, proliferation and cellular differentiation, exert a wide spectrum of biological activities selectively binding to and activating specific membrane receptors which then transfer the message to cell interior, inducing specific biochemical pathways. GFs are especially involved in the regulation of angiogenesis, a physiological process of remodelling of the vascular tissue, characterized by the branching out of a new blood vessel from a pre-existing vessel, underlining several pathologies. Molecules interfering with the molecular recognition between a GF and its receptor, and able to modulate angiogenesis, have a big pharmacologic interest. Luca D. D'Andrea, Annarita Del Gatto, Lucia De Rosa, Alessandra Romanelli and Carlo Pedone [3] show how peptides are useful tools to develop new lead compounds disrupting protein-protein interface for pharmacological applications.