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Differential gene expression of Toll‐like receptors in response to muscle injury in young and old muscles
Author(s) -
Machida Shuichi,
Kunisawa Yumi,
Peake Jonathan
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.997.15
Subject(s) - skeletal muscle , tlr2 , receptor , tlr5 , biology , cardiotoxin , gene expression , messenger rna , muscle tissue , tlr4 , endocrinology , medicine , tibialis anterior muscle , downregulation and upregulation , gene , genetics
Toll‐like receptors (TLRs) are highly conserved trans‐membrane proteins that function as pattern recognition receptors for a wide variety of infectious micro‐organisms. Recent research has indicated that TLRs are expressed in skeletal muscle. The purpose of this investigation was to determine the mRNA expression pattern of six TLRs during muscle regeneration after muscle injury in young and old muscles. To induce local muscle injury, cardiotoxin was injected into the tibialis anterior muscle of young (2 months) and old (28 months) male C57BL/6 mice. The muscles were removed 1, 3, 5, 7, and 14 days after injection. Gene expression of TLR2, TLR4, TLR5, TLR7 and TLR9 was significantly upregulated in muscle from both young and old mice after muscle injury. TLR2 mRNA expression in young muscle peaked after 1 day at a significantly higher level compared with old muscle, and then declined progressively. The expression pattern of TLR4 and TLR9 mRNA was similar in muscle from young and old mice. TLR5 mRNA expression peaked after 1 day in young mice, whereas it did not increase until after 3 days in old mice. TLR7 mRNA expression peaked after 3 days in young mice at a significantly higher level compared with old mice. These data suggest dysregulation of TLR mRNA expression may partially account for the impaired muscle regeneration of aging skeletal muscle.