Expression of Bmi-1 in Epidermis Enhances Cell Survival by Altering Cell Cycle Regulatory Protein Expression and Inhibiting Apoptosis
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The polycomb group (PcG) genes are epigenetic suppressors of gene expression that play an important role in development. In this study, we examine the role of Bmi-1 (B-cell-specific Moloney murine leukemia virus integration site 1) as a regulator of human epidermal keratinocyte survival. We identify Bmi-1 mRNA and protein expression in epidermis and in cultured human keratinocytes. Bmi-1 is located in the nucleus in cultured keratinocytes, and in epidermis it is expressed in the basal and suprabasal layers. Adenovirus-delivered Bmi-1 promotes keratinocyte survival and protects keratinocytes from stress agent-mediated cell death. This is associated with increased levels of cyclin D1 and selected cyclin-dependent kinases, and reduced caspase activity and poly(ADP-ribose) polymerase (PARP) cleavage. Bmi-1 may be involved in the maintenance of disease state, as Bmi-1 levels are elevated in transformed keratinocytes, skin tumors, and psoriasis. The presence of Bmi-1 in suprabasal non-proliferative cells of the epidermis and within a high percentage of cells within skin tumors suggests a non-stem cell pro-survival role for Bmi-1 in this tissue. Based on the suprabasal distribution of Bmi-1 in epidermis, we propose that Bmi-1 may promote maintenance of suprabasal keratinocyte survival to prevent premature death during differentiation. Such a function would help assure proper formation of the stratified epidermis.
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Xiao T, Eze U, Charruyer-Reinwald A, Weisenberger T, Khalifa A, Abegaze B Stem Cell Res Ther. 2024; 15(1):76.
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Expression and Regulatory Mechanisms of MicroRNA in Cholesteatoma: A Systematic Review.
Dzaman K, Czerwaty K, Reichert T, Szczepanski M, Ludwig N Int J Mol Sci. 2023; 24(15).
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Lin H, Pan Y, Cai S Stem Cells Transl Med. 2023; 12(5):245-257.
PMID: 37018467 PMC: 10184702. DOI: 10.1093/stcltm/szad019.
Epigenetic Mechanisms of Epidermal Differentiation.
Moltrasio C, Romagnuolo M, Marzano A Int J Mol Sci. 2022; 23(9).
PMID: 35563264 PMC: 9102508. DOI: 10.3390/ijms23094874.
Repression of the Antioxidant Pyrroloquinoline Quinone in Skin Aging Induced by Bmi-1 Deficiency.
Li J, Liu M, Liang S, Yu Y, Gu M Biomed Res Int. 2022; 2022:1732438.
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