TY - JOUR
T1 - The mRNA expression profile of metabolic genes relative to MHC isoform pattern in human skeletal muscles
AU - Plomgaard, Peter
AU - Penkowa, Milena
AU - Leick, Lotte
AU - Pedersen, Bente K
AU - Saltin, Bengt
AU - Pilegaard, Henriette
N1 - Keywords: Adult; Cells, Cultured; Energy Metabolism; Gene Expression; Gene Expression Profiling; Humans; Male; Muscle Fibers, Skeletal; Muscle Proteins; Muscle, Skeletal; Myosin Heavy Chains; Protein Isoforms; RNA, Messenger; Tissue Distribution
PY - 2006
Y1 - 2006
N2 - The metabolic profile of rodent muscle is generally reflected in the myosin heavy chain (MHC) fiber-type composition. The present study was conducted to test the hypothesis that metabolic gene expression is not tightly coupled with MHC fiber-type composition for all genes in human skeletal muscle. Triceps brachii, vastus lateralis quadriceps, and soleus muscle biopsies were obtained from normally physically active, healthy, young male volunteers, because these muscles are characterized by different fiber-type compositions. As expected, citrate synthase and 3-hydroxyacyl dehydrogenase activity was more than twofold higher in soleus and vastus than in triceps. Contrary, phosphofructokinase and total lactate dehydrogenase (LDH) activity was approximately three- and twofold higher in triceps than in both soleus and vastus. Expression of metabolic genes was assessed by determining the mRNA content of a broad range of metabolic genes. The triceps muscle had two- to fivefold higher MHC IIa, phosphofructokinase, and LDH A mRNA content and two- to fourfold lower MHC I, lipoprotein lipase, CD36, hormone-sensitive lipase, and LDH B and hexokinase II mRNA than vastus lateralis or soleus. Interestingly, such mRNA differences were not evident for any of the genes encoding mitochondrial oxidative proteins, 3-hydroxyacyl dehydrogenase, carnitine palmitoyl transferase I, citrate synthase, alpha-ketogluterate dehydrogenase, and cytochrome c, nor for the transcriptional regulators peroxisome proliferator activator receptor gamma coactivator-1alpha, forkhead box O1, or peroxisome proliferator activator receptor-alpha. Thus the mRNA expression of genes encoding mitochondrial proteins and transcriptional regulators does not seem to be fiber type specific as the genes encoding glycolytic and lipid metabolism genes, which suggests that basal mRNA regulation of genes encoding mitochondrial proteins does not match the wide differences in mitochondrial content of these muscles.
AB - The metabolic profile of rodent muscle is generally reflected in the myosin heavy chain (MHC) fiber-type composition. The present study was conducted to test the hypothesis that metabolic gene expression is not tightly coupled with MHC fiber-type composition for all genes in human skeletal muscle. Triceps brachii, vastus lateralis quadriceps, and soleus muscle biopsies were obtained from normally physically active, healthy, young male volunteers, because these muscles are characterized by different fiber-type compositions. As expected, citrate synthase and 3-hydroxyacyl dehydrogenase activity was more than twofold higher in soleus and vastus than in triceps. Contrary, phosphofructokinase and total lactate dehydrogenase (LDH) activity was approximately three- and twofold higher in triceps than in both soleus and vastus. Expression of metabolic genes was assessed by determining the mRNA content of a broad range of metabolic genes. The triceps muscle had two- to fivefold higher MHC IIa, phosphofructokinase, and LDH A mRNA content and two- to fourfold lower MHC I, lipoprotein lipase, CD36, hormone-sensitive lipase, and LDH B and hexokinase II mRNA than vastus lateralis or soleus. Interestingly, such mRNA differences were not evident for any of the genes encoding mitochondrial oxidative proteins, 3-hydroxyacyl dehydrogenase, carnitine palmitoyl transferase I, citrate synthase, alpha-ketogluterate dehydrogenase, and cytochrome c, nor for the transcriptional regulators peroxisome proliferator activator receptor gamma coactivator-1alpha, forkhead box O1, or peroxisome proliferator activator receptor-alpha. Thus the mRNA expression of genes encoding mitochondrial proteins and transcriptional regulators does not seem to be fiber type specific as the genes encoding glycolytic and lipid metabolism genes, which suggests that basal mRNA regulation of genes encoding mitochondrial proteins does not match the wide differences in mitochondrial content of these muscles.
U2 - 10.1152/japplphysiol.00183.2006
DO - 10.1152/japplphysiol.00183.2006
M3 - Journal article
C2 - 16794029
SN - 8750-7587
VL - 101
SP - 817
EP - 825
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 3
ER -
