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Fiber type specific PGC‐1α content and its relation to capillarization and mitochondrial content
Author(s) -
Gouspillou Gilles,
Sgarioto Nicolas,
Norris Brandon,
Hepple Russell Thomas
Publication year - 2013
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.27.1_supplement.1152.23
Subject(s) - tfam , skeletal muscle , mitochondrion , fiber type , immunolabeling , plantaris muscle , medicine , endocrinology , chemistry , biology , mitochondrial biogenesis , biochemistry , immunohistochemistry , soleus muscle
PGC‐1α is a central protein in skeletal muscle physiology. In addition of being the master regulator of mitochondrial biology, this coactivator of transcription has been implicated in the regulation of angiogenesis and has been shown to drive the formation of slow‐twitch fibers. The objective of the present study was, for the first time, to determine the relationship between PGC‐1α content, fiber type, capillarization, and mitochondrial content in rat skeletal muscle. To this end, serial sections of plantaris muscle were used to determine (i) fiber type (immunolabeling for MHC I, IIa, IIx, and IIb), (ii) mitochondrial content (succinate dehydrogenase stain), (iii) capillarization (Lead ATPase) and (iv) PGC‐1α content (immunolabeling). Surprisingly, we found that type IIa fibers have the highest PGC‐1α content, whereas no significant differences were observed between other fiber types. Associated with their higher PGC‐1α content, Type IIa fibers also displayed the highest mitochondrial content, followed by type I>;IIx>;IIb. However, type I displayed the highest number of capillaries per fiber perimeter, followed by type IIa>;IIx>;IIb. Although type IIa fibers show the higest PGC‐1α and mitochondrial content, our results suggest that neither basal mitochondrial content nor capillarization are directly related to differences in PGC‐1α content between fiber types in rat skeletal muscle.