Proteomes and Signalling Pathways of Antler Stem Cells

Abstract

As the only known example of complete organ regeneration in mammals, deer antler in the growing or velvet phase is of major interest in developmental biology. This regeneration event initiates from self-renewing antler stem cells that exhibit pluripotency. At present, it remains unclear how the activation and quiescence of antler stem cells are regulated. Therefore, in the present study proteins that were differentially expressed between the antler stem cells and somatic cells (facial periosteum) were identified by a gel-based proteomic technique, and analysed using Ingenuity Pathway Analysis software. Several molecular pathways (PI3K/Akt, ERK/MAPK, p38 MAPK, etc.) were found to be activated during proliferation. Also expressed were the transcription factors POU5F1, SOX2, NANOG and MYC, which are key markers of embryonic stem cells. Expression of these proteins was confirmed in both cultured cells and fresh tissues by Western blot analysis. Therefore, the molecular pathways and transcription factors identified in the current study are common to embryonic and adult stem cells. However, expression of embryonic stem cell transcription factors would suggest that antler stem cells are, potentially, an intermediary stem cell type between embryonic and the more specialized tissue-specific stem cells like those residing in muscle, fat or from a hematopoietic origin. The retention of this embryonic, pluripotent lineage may be of fundamental importance for the subsequent regenerative capacity of antlers.

Distribution of BDNF and TrkB isoforms in growing antler tissues of red deer

“…Interestingly, some of the intracellular pathways induced by TrkB isoforms, such as PI3K/Akt, regulation of actin based motility by Rho and ERK/MAPK, are in common with those significantly identified on antlerogenic and pedicle periosteum cells (Li et al, 2012).…”

iTRAQ-Based Quantitative Proteomic Analysis of the Potentiated and Dormant Antler Stem Cells

“…The primary culturing of the PPPCs and the DPPCs was conducted following the protocol described by Li et al [40]. Cells were trypsinized and transferred into T75 flasks (Nest Biotechnology, Hong Kong, China) and then cultured in dulbecco modified eagle medium (DMEM) (Life Technologies, Carlsbad, CA, USA) plus 10% FBS (Gibco, Carlsbad, CA, USA), 500 U/mL penicillin, and 500 μg/mL streptomycin (Invitrogen, Carlsbad, CA, USA) for two days before being frozen.…”

The regenerating antler blastema the derivative of stem cells resident in a pedicle stump

“…Our group was the first to study the differential expression of molecules of the PP over deer facial periosteum through 2-dimensional electrophoresis, and the signaling pathways through Ingenuity Pathway Analysis (IPA), including both PP tissues and cells collected from the pedicle stumps just prior to antler regeneration (71). In the study, 98 proteins were detected to be overexpressed in the PP.…”