QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Larsen, A. E. Articles by Crowe, T. C. Search for Related Content PubMed PubMed Citation Articles by Larsen, A. E. Articles by Crowe, T. C.

---

Biochemical, Molecular, and Genetic Mechanisms

Conjugated Linoleic Acid Suppresses Myogenic Gene Expression in a Model of Human Muscle Cell Inflammation^1,2

School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria 3125, Australia

^* To whom correspondence should be addressed. E-mail: tim.crowe{at}deakin.edu.au.

Proinflammatory cytokines, such as tumor necrosis factor (TNF)-, contribute to muscle wasting in inflammatory disorders, where TNF acts to regulate myogenic genes. Conjugated linoleic acid (CLA) has shown promise as an antiproliferative and antiinflammatory agent, leading to its potential as a therapeutic agent in muscle-wasting disorders. To evaluate the effect of CLA on myogenesis during inflammation, human primary muscle cells were grown in culture and exposed to varying concentrations of TNF and the cis-9, trans-11 and trans-10, cis-12 CLA isomers. Expression of myogenic genes (Myf5, MyoD, myogenin, and myostatin) and the functional genes creatine kinase (CK) and myosin heavy chain (MHC IIx) were measured by real-time PCR. TNF significantly downregulated MyoD and myogenin expression, whereas it increased Myf5 expression. These changes corresponded with a decrease in both CK and MHC IIx expression. Both isomers of CLA mimicked the inhibitory effect of TNF treatment on MyoD and myogenin expression, whereas myostatin expression was diminished in the presence of both isomers of CLA either alone or in combination with TNF. Both isomers of CLA decreased CK and MHC IIx expression. These findings demonstrate that TNF can have specific regulatory effects on myogenic genes in primary human muscle cells. A postulated antiinflammatory role of CLA in myogenesis appears more complex, with an indication that CLA may have a negative effect on this process.