HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Reynders, V. Articles by Decramer, M. Search for Related Content PubMed PubMed Citation Articles by Reynders, V. Articles by Decramer, M.

Alterations in gene expression in hamster diaphragm after emphysema and lung volume reduction surgery

¹ Respiratory Muscle Research Unit, Laboratory of Pneumology, ² Thoracic Surgery Division and ³ Laboratory for Experimental Medicine and Endocrinology, University Hospitals, Katholieke Universiteit Leuven, Leuven, Belgium

CORRESPONDENCE: M. Decramer, Respiratory Division, University Hospital, Herestraat 49, B-3000, Leuven, Belgium. Fax: 3216347126. E-mail: marc.decramer@uz.kuleuven.ac.be

Keywords: emphysema, Id-proteins, IGF-I, muscle plasticity, myogenic regulatory factors, RT-PCR

Received: November 22, 2001
Accepted January 18, 2002

The study was supported by Fonds voor Wetenschappelijk Onderzoek-Vlaanderen grant #G.0175.99 and Katholieke Universiteit Leuven Research Foundation grant #OT98/27. G. Gayan-Ramirez is a postdoctoral fellow of the Fonds voor Wetenschappelijk Onderzoek-Vlaanderen.

The authors have demonstrated previously that emphysema and lung volume reduction surgery (LVRS) resulted in a significant shift of type IIx/b to type IIa fibres in the diaphragm of hamsters with elastase-induced emphysema. To explore the mechanisms leading to this fibre switching, the mRNA expression of the myogenic regulatory factors, the inhibitors of DNA binding proteins (Id-proteins) and insulin-like growth factor-I were examined.

Ribonucleic acid was extracted from the diaphragm of control, emphysematous, emphysematous and sham operated and LVRS hamsters and subjected to reverse transcriptase polymerase chain reaction.

Compared to control, the ratio MyoD to myogenin declined with emphysema, sham and even more after LVRS, due to a decrease in MyoD mRNA and an increase in myogenin mRNA. Similarly, compared to control, Id-1 protein mRNA levels decreased significantly in sham and even more in LVRS. Id-2 protein mRNA levels decreased in all groups, but reached statistical significance in LVRS only, compared to control.

In conclusion: 1) the reduced MyoD/myogenin ratio may be the mechanism of the shift to a slower fibre type, 2) the decreased MyoD/myogenin ratio in lung volume reduction surgery animals suggests that lung volume reduction surgery enhances rather than decreases the load placed on the diaphragm and 3) the observed down-regulation of the inhibiting factors may facilitate the diaphragm adaptation to overload.

This article has been cited by other articles:

				H. Degens, A. K. Swisher, Y. F. Heijdra, P. M. Siu, P. N. Richard Dekhuijzen, and S. E. Alway Apoptosis and Id2 expression in diaphragm and soleus muscle from the emphysematous hamster Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R135 - R144. [Abstract] [Full Text] [PDF]

				M. I. Lewis, M. Fournier, X. Da, H. Li, Z. Mosenifar, R. J. McKenna Jr, and A. H. Cohen Short-term Influences of Lung Volume Reduction Surgery on the Diaphragm in Emphysematous Hamsters Am. J. Respir. Crit. Care Med., October 1, 2004; 170(7): 753 - 759. [Abstract] [Full Text] [PDF]