Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
Antimicrobial peptide defensin: Identification of novel isoforms and the characterization of their physiological roles and their significance in the pathogenesis of diseases
Yasuhiro YAMAGUCHIYasuyoshi OUCHI
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2012 Volume 88 Issue 4 Pages 152-166


Defensins comprise a family of cationic antimicrobial peptides containing a specific six-cysteine motif. Their contribution to the host defense against microbial invasion and the control of normal flora have been previously described. Some of the β-defensin isoforms are predominantly expressed in the epididymis and showed a region-specific expression pattern in the epididymis, which thus suggested that these isoforms may possess epididymis-specific functions in addition to antimicrobial activities. A sequence variant of the β-defensin 126 gene has been shown to be associated with reductions in the human sperm function, thus supporting this hypothesis. Furthermore, defensins have the capacity to chemoattract immune cells and induce the secretion of inflammatory cytokines. Mice expressing human neutrophil α-defensin showed more severe lung injuries after the aspiration of acidic contents than did control mice. Recent investigations regarding copy number variations of human defensin genes also suggest the significance of defensin in the pathogenesis or the worsening of chronic obstructive pulmonary diseases, sepsis and psoriasis.

(Communicated by Kumao TOYOSHIMA, M.J.A.)

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© 2012 The Japan Academy
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