Method for promoting mesenchymal stem and lineage-specific cell proliferation

A method of accelerating the proliferation of mesenchymal stem and lineage specific cells comprising contacting the mesenchymal stem and lineage-specific cells with an amount effective to accelerate proliferation of the mesenchymal stem and lineage-specific cells of at least one active agent comprising a sequence of at least six contiguous amino acids of groups R1-R8 in the sequence of general formula I

• R1-R2-R3-R4-R5-R6-R7-R8
• wherein RA is selected from the group consisting of H, Asp, Glu, Asn, 1-aminocyclopentane carboxylic acid, Ala, N,N-dimethylglycyl, Pro, 1-carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt, Glu(NH2), Gly, Asp(NH2) and Succinyl, or is absent;
• wherein RB is selected from the group consisting of Arg, Lys, Ala, Orn, Ser(Ac), Sar, D-Arg and D-Lys;
• R3 is selected from the group consisting of Val, Ala, Leu, Nle, Ile, Gly, Pro, Aib, Acpc and Tyr;
• R4 is selected from the group consisting of Tyr, diphospho tyrosine, Thr, Ser, homoserine and aza-α′-homo-L-tyrosyl;
• R5 is selected from the group consisting of Ile, Ala, Leu, Nle, Val and Gly;
• R6 is selected from the group consisting of His, Arg and 6-NH2-Phe;
• R7 is selected from the group consisting of Pro and Ala;
• and
• R8 is selected from the group consisting of Phe, p-bromo-L-phenylalanyl, Ile and Tyr.