A macrophage migration inhibitory factor is expressed in the differentiating cells of the eye lens.
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Wistow GJ, Shaughnessy MP, Lee DC, Hodin J, Zelenka PS
A macrophage migration inhibitory factor is expressed in the differentiating cells of the eye lens.
Proc Natl Acad Sci U S A. 1993 Feb 15;90(4):1272-5.
- PubMed ID
- 7679497 [ View in PubMed]
- Abstract
A discrete 10-kDa polypeptide (10K) is expressed from early stages in the embryonic chicken lens. Since this has potential as a marker for lens cell development, chicken 10K and its homologues from mouse and human lenses were identified by protein sequencing and cloning. Surprisingly, lens 10K proteins appear to be identical to a lymphokine, macrophage migration inhibitory factor (MIF), originally identified in activated human T cells. Using microdissection and PCR techniques, we find that expression of 10K/MIF is strongly correlated with cell differentiation in the developing chicken lens. Northern blot analysis shows that 10K/MIF is widely expressed in mouse tissues. These results suggest that proteins with MIF activity may have roles beyond the immune system, perhaps as intercellular messengers or part of the machinery of differentiation itself. Indeed, partial sequence of other small lens proteins identifies another MIF-related protein (MRP8) in calf lens. The relatively abundant expression of MIF in lens may have clinical significance, with the possibility of involvement in ocular inflammations that may follow damage to the lens.