A Novel Mouse β-Defensin, mBD-6, Predominantly Expressed in Skeletal Muscle

Yasuhiro Yamaguchi,Shigetomo Fukuhara,Takahide Nagase,Tetsuji Tomita,Shigemi Hitomi,Satoshi Kimura,Hiroki Kurihara,Yasuyoshi Ouchi

doi:10.1074/jbc.m104149200

Abstract

Defensins comprise a family of cationic antimicrobial peptides that is characterized by the conserved 6 cysteine residues. They are expressed in the epithelial cells of various organs and are identified as key elements in the host defense system at the mucosal surface. We isolated a novel mouse beta-defensin gene from the bacterial artificial chromosome DNA containing the mouse beta-defensin-3 gene. The full-length cDNA was cloned from skeletal muscle cDNA and called mouse beta-defensin-6 (mBD-6). The predicted peptide conserved the 6-cysteine motif and had 59% amino acid sequence identity with mouse beta-defensin-3 and 59% identity with mouse beta-defensin-4. We demonstrated the expression of mBD-6 in skeletal muscle in addition to the esophagus, tongue, and trachea. In animal models of endotoxemia, mBD-6 expression was also induced in the lung. mBD-6 showed potent antimicrobial activity against Escherichia coli and would play an important role in host defense in the esophagus, airways, and skeletal muscle. mBD-6 is the first reported beta-defensin predominantly expressed in skeletal muscle. This unique tissue specificity suggests some novel physiological roles of this peptide family.

Highlights

Defensins are cationic antimicrobial peptides that include six specific cysteine residues and can be divided into the ␣- and ␤-defensin subfamilies
In animal models of endotoxemia, mBD-6 expression was induced in the lung. mBD-6 showed potent antimicrobial activity against Escherichia coli and would play an important role in host defense in the esophagus, airways, and skeletal muscle. mBD-6 is the first reported ␤-defensin predominantly expressed in skeletal muscle
The first mammalian ␤-defensin was discovered from bovine respiratory tract and was named tracheal antimicrobial peptide [5]

Summary

Introduction

Defensins are cationic antimicrobial peptides that include six specific cysteine residues and can be divided into the ␣- and ␤-defensin subfamilies. The full-length cDNA was cloned from skeletal muscle cDNA and called mouse ␤-defensin-6 (mBD-6). We demonstrated the expression of mBD-6 in skeletal muscle in addition to the esophagus, tongue, and trachea.

Results

Conclusion