Identification of Lactoferrin as a Human Dedifferentiation Factor Through the Studies of Reptile Tissue Regeneration Mechanisms

Abstract

In this study, we performed two-dimensional electrophoresis with protein extracts from lizard tails, and analyzed the protein expression profiles during the tissue regeneration to identify the dedifferentiation factor. As a result, we identified 18 protein spots among total of 292 spots, of which proteins were specifically expressed during blastema formation. We selected lactoferrin as a candidate because it is the mammalian homolog of leech-derived tryptase inhibitor, which showed the highest frequency among the 18 proteins. Lactoferrin was specifically expressed in various stem cell lines, and enhanced the efficiency of iPSC generation upto approximately 7-fold relative to the control. Furthermore, lactoferrin increased the efficiency by 2-fold without enforced expression of Klf4. These results suggest that lactoferrin may induce dedifferentiation, at least partly by increasing the expression of Klf4.

Review: The Regenerating Tail Blastema of Lizards as a Model to Study Organ Regeneration and Tumor Growth Regulation in Amniotes

“…Both progenitor (stem) cells and de‐differentiation of cells of the connective tissue, muscle, periosteum, cartilage, and ependyma appear to contribute to the blastema (Quattrini, ; Bae et al, ; Alibardi, , , ; Londono et al, ). After 2–8 days from tail loss, proliferating cells, evidenced by proliferation markers (thymidine, 5BrdU, PCNA, PhosphohistoneH3, etc), appear among the injured tissues of the stump and form an epimorphic blastema (Fig.…”

“…The few two‐dimensional proteome analysis on regenerating tissues of lizards have shown the variations of specific protein spots during regeneration, but only in few cases these proteins have been identified (Bae et al, ; Alibardi, ; Hong and Thornton, ; Murawala et al, ). Among the proteins most are metabolic enzymes, protease inhibitors, immune proteins, cytoskeletal proteins, and iron carrying proteins (lactoferrin and transferrin).…”

Review: Biological and Molecular Differences between Tail Regeneration and Limb Scarring in Lizard: An Inspiring Model Addressing Limb Regeneration in Amniotes

“…Also the presence of an upregulated gene coding for a MARCK‐like protein in the transcriptome of the tail and limb of the lizard Podarcis muralis (Vitulo et al, ), considered a specific initiator of limb regeneration in amphibians (Sugiura et al, ), suggests that also in lizard this protein is among the initial factors that trigger tail regeneration. Lactoferrin and kfl4 (Kruppel‐like factor 4) have been proposed among dedifferentiating proteins factors operating on tissues after tail amputation in lizard (Bae et al., ).…”

Spot the difference: Solving the puzzle of hidden pictures in the lizard genome for identification of regeneration factors

“…In addition to the above genomic and transcriptomic approaches, proteomic analysis has also been done to study the mechanisms of tail regeneration. The first gene identified as a dedifferentiation factor from proteomic studies in lizards was a lactoferrin, reported by Bae et al in 2014 (31) . Many case of tissue regeneration in lower animals involve cellular dedifferentiation to form a blastema, followed by redifferentiation and subsequent regenerative proliferation (32) .…”