Immunolocalization of Periostin-Like-Factor and Periostin During Embryogenesis
Shimei Zhu 1, Mary F. Barbe 1, Neilay Amin 1, Shobha Rani 1, Steven N. Popoff 1, Fayez F. Safadi 1 and Judith Litvin 1*
1 Department of Anatomy and Cell Biology (SZ,MFB,NA,SR,SNP,FFS,JL), Musculoskeletal Research Group (MFB,SNP,FFS,JL), and Department of Physical Therapy, College of Health Professions (MFB), Temple Medical School, Philadelphia, Pennsylvania
* To whom correspondence should be addressed. E-mail: Judith.litvin{at}temple.edu .
Submitted on July 23, 2007
Accepted on 15 November 2007
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Abstract |
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Periostin-Like-Factor (PLF) and Periostin are alternatively spliced messenger RNAs. Our findings will be the first to show similarities and differences between PLF and Periostin location using isoforms-specific antibodies. The differences in when and where they are present during mouse embryogenesis suggest that they may have different functions. Using immunostaining techniques, we observed that PLF was highly expressed at 12.5 days post-conception (dpc) in intermediate and outer zones of most brain regions, spinal cord, cranial and spinal nerves, and chondrocytes in developing bone and in the heart wall. By 16.5 dpc, PLF was also present in ameloblasts and odontoblasts in developing teeth and by 19.5 dpc, PLF was present at low levels only in vagal nerve bundles, discrete white matter bundles in the brain, and chondrocytes of developing ribs. Periostin on the other hand, was absent at 12.5 dpc from dorsal spinal cord as well as cranial and spinal nerves. By 16.5 dpc, Periostin was present in many spinal nerves, but absent thereafter and at 19.5 dpc, Periostin was present in chondrocytes in developing bone but not in neural tissues. The different spatial and temporal location of PLF and Periostin in cartilage and bone cells suggests different roles for these proteins in endochondral bone formation. The early expression of PLF in brain differentiation zones and in developing axon bundles and nerves, suggests that it may facilitate axon growth.
Key Words:
Periostin-Like-Factor, embryogenesis, heart, brain, spinal cord, nerves