title: Mitochondrial biogenesis in striated muscles: rapid induction of citrate synthase mRNA by nerve stimulation.
abstract: Tonic contractile activity induces mitochondrial biogenesis in mammalian skeletal muscles, necessitating regulation of both nuclear and mitochondrial genes encoding mitochondrial proteins. In this study we compared the time course of induction of citrate synthase (CS) mRNA, a nuclear gene product, to that of genes encoded by mitochondrial DNA during the adaptive response to indirect nerve stimulation in tibialis anterior muscles of adult rabbits. A CS cDNA probe was prepared from a rabbit heart cDNA library by the polymerase chain reaction using synthetic oligonucleotide primers based on the published sequence of the porcine gene. This cDNA probe hybridized to a single band on Northern blots of total or polyadenylated RNA from adult rabbit tissues. Nerve stimulation for 3 days increased the abundance of CS mRNA relative to total cellular RNA by 2.3 +/- 0.2-fold (mean +/- SE, n = 8; P less than 0.01). In contrast, CS enzyme activity and mitochondrial RNA transcripts were not significantly increased at this time point. However, when nerve stimulation was continued for 21 days, the increases in CS mRNA and mitochondrial RNAs were similar. These results support the hypothesis that genetic signaling mechanisms triggered by neural input are sensed initially within the nucleus and that expression of mitochondrial genes is regulated as a secondary event.
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710.
authors.forename: B H
authors.initials: BH
authors.lastname: Annex
authors.forename: W E
authors.initials: WE
authors.lastname: Kraus
authors.forename: G L
authors.initials: GL
authors.lastname: Dohm
authors.forename: R S
authors.initials: RS
authors.lastname: Williams
mesh_terms: D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002950:Citrate (si)-Synthase / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D004558:Electric Stimulation; D015870:Gene Expression / Q000187:drug effects; D015723:Gene Library; D008931:Mitochondria, Muscle / Q000201:enzymology*; D008969:Molecular Sequence Data; D009119:Muscle Contraction; D009132:Muscles / Q000294:innervation*; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D010543:Peroneal Nerve / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D011817:Rabbits; D012689:Sequence Homology, Nucleic Acid; D013552:Swine
chemical_list: D004272:DNA, Mitochondrial; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D002950:Citrate (si)-Synthase