A new matrikine-derived peptide up-regulates longevity genes for improving extracellular matrix architecture and connections of dermal cell with its matrix.

OBJECTIVE: Skin extracellular matrix (ECM) is a dense and well-organized structure produced by fibroblasts. This ECM transduces environmental mechano-signals to cell nucleus through the integrin-actin complex, thus triggering ECM protein syntheses. The aim of this study was to discover a novel peptide, structurally related to dermal matrikines, that promotes syntheses of ECM components. METHODS AND RESULTS: Screening tests with 120 peptides were carried out by using normal dermal human fibroblasts (HF). As a result, one candidate of interest was isolated, the N-Prolyl Palmitoyl Tripeptide-56 Acetate (PP56), which increases collagen and fibronectin productions at gene and/or protein levels. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a recent and innovative analytical technology, in addition to more traditional techniques, it was showed that two metabolic pathways were significantly modulated: one for collagen production and one for actin. Moreover, this peptide up-regulated the transcription of Forkhead Box O (FOXO) and sestrin messenger RNAs (mRNA), leading to production of proteins involved into longevity and more recently in collagen production. RESULTS: Results indicated that this peptide is a potential candidate to improve ECM density and organization in a new way.

OBJECTIF: La matrice extracellulaire cutanée (MEC) est une structure dense et bien organisée produite par les fibroblastes. Cette MEC transduit les mécano-signaux environnementaux vers le noyau de la cellule par le biais du complexe intégrine-actine, ce qui déclenche la synthèse de protéines par la MEC. Le but de cette étude était de découvrir un nouveau peptide, structurellement apparenté aux matrikines dermiques, qui favorise la synthèse des composants de la MEC. MÉTHODES ET RÉSULTATS: Des tests de criblage avec 120 peptides ont été réalisés en utilisant des fibroblastes humains dermaux normaux (HF). Un candidat d'intérêt a été isolé, l'acétate de N-Prolyl Palmitoyl-Tripeptide-56 (PP56), qui augmente les productions de collagène et de fibronectine aux niveaux du gène et / ou de la protéine. En utilisant une technologie analytique récente et innovante, la spectrométrie de masse par chromatographie liquide-tandem (LC-MS / MS) ainsi que des techniques plus traditionnelles, il a été démontré que deux voies métaboliques sont modulées de manière significative: une pour la production de collagène et une pour l'actine. En outre, ce peptide a régulé positivement la transcription des ARN messagers (ARNm), du facteur de transcription Forkhead Box (FOXO) et de la sestrine, conduisant à la production de protéines impliquées dans la longévité et plus récemment dans la production de collagène. RÉSULTATS: Les résultats ont indiqué que ce peptide est un candidat potentiel pour améliorer la densité et l'organisation de la MEC d'une manière nouvelle.

Inhibitors of tripeptidyl peptidase II. 2. Generation of the first novel lead inhibitor of cholecystokinin-8-inactivating peptidase: a strategy for the design of peptidase inhibitors.

The cholecystokinin-8 (CCK-8)-inactivating peptidase is a serine peptidase which has been shown to be a membrane-bound isoform of tripeptidyl peptidase II (EC 3.4.14.10). It cleaves the neurotransmitter CCK-8 sulfate at the Met-Gly bond to give Asp-Tyr(SO(3)H)-Met-OH + Gly-Trp-Met-Asp-Phe-NH(2). In seeking a reversible inhibitor of this peptidase, the enzymatic binding subsites were characterized using a fluorimetric assay based on the hydrolysis of the artificial substrate Ala-Ala-Phe-amidomethylcoumarin. A series of di- and tripeptides having various alkyl or aryl side chains was studied to determine the accessible volume for binding and to probe the potential for hydrophobic interactions. From this initial study the tripeptides Ile-Pro-Ile-OH (K(i) = 1 microM) and Ala-Pro-Ala-OH (K(i) = 3 microM) and dipeptide amide Val-Nvl-NHBu (K(i) = 3 microM) emerged as leads. Comparison of these structures led to the synthesis of Val-Pro-NHBu (K(i) = 0.57 microM) which served for later optimization in the design of butabindide, a potent reversible competitive and selective inhibitor of the CCK-8-inactivating peptidase. The strategy for this work is explicitly described since it illustrates a possible general approach for peptidase inhibitor design.

Biologically active peptides: from a laboratory bench curiosity to a functional skin care product.

Small, biologically active peptides (short sequences of amino acids) were first described about 40 years ago: TRH, angiotensin, vasopressin, oxytocin, bradykinin. Since then, many more peptides have been isolated from mammalian tissue and organs, and their activity investigated. Essentially, these molecules play a hormonal (messenger) role: released at one point in the body, they act at specific receptor sites at different locations in the organism. Mostly the peptides are transported from the site of release to the site of biological activity through the blood or lymphatic fluid. The use of these molecules in cosmetics does not appear obvious, as the topical application of these highly soluble, fragile and extremely expensive molecules seems inappropriate, and systemic effects (blood transport) are not desired. This paper shows that the obstacles to using highly specific, powerful peptides as 'actives' in cosmetic products can be overcome. Cosmetically interesting activities such as stimulation of collagen synthesis, chemotaxis, anti-stinging effects and others, can be observed and substantiated with chemically modified peptide sequences. Long chain fatty acid conjugates improve skin penetration, specific activity and economic feasibility of these molecules.