Tetrapeptides and compositions comprising tetrapeptides

According to the invention, a tetrapeptide capable of inducing up-regulation of dermal extracellular matrix protein is provided, and the tetrapeptide has the following amino acid sequences: U-(SEQ ID No: 1)-Z, U-(SEQ ID No: 2)-Z, U-(SEQ ID No: 3)-Z, U-(SEQ ID No: 4)-Z, U-(SEQ ID No: 5)-Z, U-(SEQ ID No: 6)-Z, U-(SEQ ID No: 7)-Z, U-(SEQ ID No: 9)-Z, U-(SEQ ID No: 12)-Z, U-(SEQ ID No: 14)-Z, U-(SEQ ID No: 15)-Z, U-(SEQ ID No: 16)-Z, and U-(SEQ ID No: 1). Wherein, at the N-terminus, U is selected from the group consisting of CO-R1,-SO2-R1 or biotin-based groups, and, at the C-terminus, Z is selected from the group consisting of OH, OR1, NHR1 or NR1R2 wherein R1 and R2 are independently selected from the group consisting of alkyl, aryl, aralkyl, alkylaryl, alkoxy, sugar and aryloxy groups, the present invention relates to compounds which may be linear, branched, cyclic, polycyclic, unsaturated, hydroxylated, carbonylated, phosphorylated and/or sulfur-containing groups comprising from 1 to 24 carbon atoms and which