Epigenetic inhibitor zebularine activates ear pinna wound closure in the mouse

Abstract

Background Most studies on regenerative medicine focus on cell-based therapies and transplantations. Small-molecule therapeutics, though proved effective in different medical conditions, have not been extensively investigated in regenerative research. It is known that healing potential decreases with development and developmental changes are driven by epigenetic mechanisms, which suggests epigenetic repression of regenerative capacity. Methods We applied zebularine, a nucleoside inhibitor of DNA methyltransferases, to stimulate the regenerative response in a model of ear pinna injury in mice. Findings We observed the regeneration of complex tissue that was manifested as improved ear hole repair in mice that received intraperitoneal injections of zebularine. Six weeks after injury, the mean hole area decreased by 83.2 ± 9.4% in zebularine-treated and by 43.6 ± 15.4% in control mice (p < 10 −30 ). Combined delivery of zebularine and retinoic acid potentiated and accelerated this effect, resulting in complete ear hole closure within three weeks after injury. We found a decrease in DNA methylation and transcriptional activation of neurodevelopmental and pluripotency genes in the regenerating tissues. Interpretation This study is the first to demonstrate an effective induction of complex tissue regeneration in adult mammals using zebularine. We showed that the synergistic action of an epigenetic drug (zebularine) and a transcriptional activator (retinoic acid) could be effectively utilized to induce the regenerative response, thus delineating a novel pharmacological strategy for regeneration. The strategy was effective in the model of ear pinna regeneration in mice, but zebularine acts on different cell types, therefore, a similar approach can be tested in other tissues and organs.

Imunofan—RDKVYR Peptide—Stimulates Skin Cell Proliferation and Promotes Tissue Repair

“…As the IM peptide showed safety profile and remarkable transcriptomic responses in in vitro tests, we decided to conduct a preliminary experiment in animals. Ear punch wound is a model of tissue repair which has been found useful in testing the pro-regenerative activity of pharmacological agents [ 9 ]. Measurements of ear hole closure are made to estimate the regenerative effects.…”

“…There are few animal models used for assessing the potential pro-regenerative activity of chemical compounds. The ear punch wound model in mice, though simple to perform, is a powerful model of complex tissue regeneration in mammals [ 9 ]. The experiment involves making a 2 mm hole in the center of ear pinna in normal laboratory mice, such as BALB/c ad C57BL/6J.…”

“…The primer sequences are listed in Supplementary Table S4 . The transcript levels were determined using the 2 −ΔCt method relative to Actb and Tbp [ 9 , 26 ].…”

A review of epigenetic regulation in wound healing: Implications for the future of wound care

“…Zebularine is a methyltransferase inhibitor similar to 5‐aza‐dc but is significantly less toxic in vivo 105,106 . When applied to wounds, closure is significantly accelerated, an effect that appears to be regenerative in nature through the activation of a plethora of neurodevelopmental genes 105 .…”

“…Zebularine is a methyltransferase inhibitor similar to 5‐aza‐dc but is significantly less toxic in vivo 105,106 . When applied to wounds, closure is significantly accelerated, an effect that appears to be regenerative in nature through the activation of a plethora of neurodevelopmental genes 105 . Besides pharmacological modulation, even the application of negative pressure can induce local changes in wound bed methylation thereby activating the wound healing response 107 .…”