A Macrophage Migration Inhibitory Factor is Expressed in the Differentiating Cells of the Eye Lens

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 90; no. 4; pp. 1272 - 1275
• Main Authors: Wistow, Graeme J., Shaughnessy, Michael P., Lee, Douglas C., Hodin, Jason, Zelenka, Peggy S.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 15-02-1993; National Acad Sciences; National Academy of Sciences
• Subjects: Amino Acid Sequence; Analysis of the immune response. Humoral and cellular immunity; Animals; Animals, Newborn; Base Sequence; Biological and medical sciences; Blotting, Northern; cDNA; Cell Differentiation - immunology; Cellular differentiation; Chick Embryo; Chickens; Complementary DNA; differentiation; DNA - genetics; DNA - isolation & purification; Epithelial cells; expression; eye lens; Fiber cells; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Gene Library; genes; Humans; Immunity (Disease); Immunobiology; Lens, Crystalline - cytology; Lens, Crystalline - embryology; Lens, Crystalline - immunology; Lymphokines, interleukins ( function, expression); Macrophage Migration-Inhibitory Factors - biosynthesis; Macrophage Migration-Inhibitory Factors - genetics; Macrophages; Medical research; Messenger RNA; Mice; migration inhibitory factor; Molecular Sequence Data; nucleotide sequence; Polymerase Chain Reaction - methods; predictions; Proteins; Regulatory factors and their cellular receptors; RNA; RNA - genetics; RNA - isolation & purification; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; T lymphocytes; T-Lymphocytes - immunology; Embryonic development; Embryo; Cytokine; Primary structure; Cell differentiation; Gene expression; Eye; Vertebrata; Lens; Chicken; Aves; Molecular cloning; Localization
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.90.4.1272

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.