Divergent effects of exercise training on membrane bound lipid binding protein expression in human skeletal muscle.

<p>Protein concentration of total crude membrane (TCM) fractions before and after 8 weeks of exercise training were determined and equal protein amounts were resolved by SDS-PAGE and membranes were immunoblotted using antibodies specific for FATP1, FATP4, FAT/CD36 and FABPpm. β-actin was run on membranes as control and was unchanged with exercise training. Eight weeks of endurance exercise training resulted in reduced FATP1 protein expression in skeletal muscle (A). In contrast, (B) FATP4 and (C) FABPpm protein expression was increased after the training intervention compared to before training. FAT/CD36 protein expression was similar before and after training (D). Representative Western blots of protein levels before (Pre) and after the exercise training period (Post) from the same subjects are shown (E). Black bars represents pre training values and grey bars represents post training values. **; <i>p</i><0.01.</p

Representative images of the proteins analyzed in total crude membranes (TCM) and soluble cytocolic fractions (Cytosol) from human vastus lateralis muscle are shown.

<p>Protein concentration of TCM and cytosol fractions pre- and post training were determined and equal protein amounts were resolved by SDS-PAGE and membranes were immunoblotted using antibodies specific for FATP1; fatty acid transport protein 1 (63 kDa) and FATP4; fatty acid transport protein 4 (72 kDa), FAT/CD36; fatty acid translocase CD36 (88 kDa), FABPpm; membrane bound fatty acid binding protein (43 kDa), FABPc; cytoplasmic fatty acid binding protein (14 kDa), ACBP; acyl-CoA binding protein (10 kDa), and Caveolin 1 (22 kDa), Caveolin 3 (18 kDa). All Western blots were run in parallel with molecular weight markers. Relevant molecular weight markings above and below each analyzed protein are indicated.</p

The Caveolae proteins Caveolin1 and Caveolin 3 were unaffected by exercise training.

<p>Eight weeks of endurance exercise training did not affect (A) Caveolin 1 and (B) Caveolin 3 protein levels. Protein concentration of TCM fractions pre- and post training were determined and equal protein amounts were resolved by SDS-PAGE and membranes were immunoblotted using antibodies specific for Caveolin 1 and Caveolin 3. β-actin was run on membranes as control and was unchanged with exercise training. Representative Western blots of protein levels before (Pre) and after the exercise training period (Post) from the same subjects are shown (C). Black bars represents pre training values and grey bars represents post training values.</p

Exercise performance parameters.

<p>Data are means ± SE.</p><p>*p<0.05;</p><p>**p<0.01 compared with Pre Training, <i>n = 8</i>.</p

Association between lipid oxidation and exercise training induced adaptations in FATP4 protein expression in human skeletal muscle.

<p>Eight weeks of endurance exercise training resulted in a shift in substrate choice towards a higher FA utilization during submaximal exercise. This training induced adaptation was associated with the observed increase in FATP4 protein expression.</p

Subject characteristics.

<p>Data are means ± SE.</p><p>*p<0.05;</p><p>**p<0.01 compared with Pre Training, <i>n = 8</i>.</p

No response of exercise training on soluble lipid binding protein expression in human skeletal muscle.

<p>Eight weeks of endurance exercise training did not affect (A) FABPc or (B) ACBP protein levels in human skeletal muscle. Protein concentration of cytosol fractions pre- and post training were determined and equal protein amounts were resolved by SDS-PAGE and membranes were immunoblotted using antibodies specific for FABPc and ACBP. β-tubulin was run on membranes as control and was unchanged with exercise training. Representative Western blots of protein levels before (Pre) and after the exercise training period (Post) from the same subjects are shown (C). Black bars represents pre training values and grey bars represents post training values.</p

Body composition and metabolic characterization.

<p>Body composition, VO2 and RER were determined in young and old AMPK KD mice and WT littermates on chow diet (CHO) or in old mice after 17 weeks of high fat diet (FA).</p>‡<p>Main effect of fasting vs. fed conditions, p<0.001.</p>#<p>Main effect of diet, p<0.01.</p>$<p>Main effect of age, p<0.005.</p>†<p>Main effect of genotype, p<0.05. Values are means ± SE. n = 7–16.</p

TBC1D1 Thr590 phosphorylation.

<p>Basal (0 µU/ml) and insulin (500 µU/ml) stimulated TBC1D1 Thr590 phosphorylation measured by Western blot analyses in m. Soleus (SOL) and m. Extensor Digitorum Longus (EDL). Measurements were made in young and old AMPK KD mice and WT littermates on chow diet (CHO) or in old mice after 17 weeks of high fat diet (FA). *: Main effect of insulin, p<0.001. #: Main effect of diet p<0.001. †: Main effect of genotype, p<0.05. Values are means ± SE. n = 11–15.</p

Protein content of GLUT4, HK2, TBC1D1, TBC1D4, Akt2 and TRB-3.

<p>Protein content of GLUT4 (A), HK2 (B), TBC1D1(C), TBC1D4 (D), Akt2 (E) and TRB-3 (F) was measured by Western blot analyses in basal muscle samples from m. Soleus (SOL) and m. Extensor Digitorum Longus (EDL). Measurements were made in young and old AMPK KD mice and WT littermates on chow diet (CHO) or in old mice after 17 weeks of high fat diet (FA). #: Main effect of diet, p<0.05. $: Main effect of age, p<0.05. †: Main effect of genotype, p<0.05. Values are means ± SE. n = 11–15.</p