Pleiotrophin (Osteoblast-Specific Factor-1, OSF-1) contains 136 amino acid residues. The sequence is very rich in cationic amino acids (24% of the residues); lysine cluster sequences are found in the N-terminal and C-terminal ends of the structure.
The OSF-1 gene was shown by Northern blotting analysis to be expressed in mouse calvarial osteoblast-enriched cells and in mouse brain tissues, but not in thymus, spleen, kidney, liver, lung, testis or heart. Pleiotrophin has the ability to promote adhesion, migration, expansion, and differentiation of human osteoprogenitor cells. In addition to certain types of cancer, the embryonic growth and differentiation factor pleiotrophin is found also in adults in inflammatory diseases. In osteoarthritis, pleiotrophin is especially expressed in early stages, and its concentrations in the synovial fluid could serve as a marker for the progress of the disease. Pleitrophin might be involved in cartilage repair in osteoarthritis, in particular, in earlier stages. References: • Ulbricht U, Brockmann MA, Aigner A, Eckerich C, Muller S, Fillbrandt R, Westphal M, Lamszus K. Expression and function of the receptor protein tyrosine phosphatase zeta and its ligand pleiotrophin in human astrocytomas. J Neuropathol Exp Neurol. 2003 Dec; 62(12): 1265-75.
• Hida H, Jung CG, Wu CZ, Kim HJ, Kodama Y, Masuda T, Nishino H. Pleiotrophin exhibits a trophic effect on survival of dopaminergic neurons in vitro. Eur J Neurosci. 2003 May; 17(10): 2127-34.
• Pufe T, Bartscher M, Petersen W, Tillmann B, Mentlein R. Pleiotrophin, an embryonic differentiation and growth factor, is expressed in osteoarthritis. Osteoarthritis Cartilage. 2003 Apr; 11(4): 260-4.
• Pufe T, Bartscher M, Petersen W, Tillmann B, Mentlein R. Expression of pleiotrophin, an embryonic growth and differentiation factor, in rheumatoid arthritis. Arthritis Rheum. 2003 Mar; 48(3): 660-7.
• Muramatsu T. Midkine and pleiotrophin: two related proteins involved in development, survival, inflammation and tumorigenesis. J Biochem (Tokyo). 2002 Sep; 132(3): 359-71. Review.
• Deuel TF, Zhang N, Yeh HJ, Silos-Santiago I, Wang ZY. Pleiotrophin: a cytokine with diverse functions and a novel signaling pathway. Arch Biochem Biophys. 2002 Jan 15; 397(2): 162-71. |
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