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PGC1α -1 Nucleosome Position and Splice Variant Expression and Cardiovascular Disease Risk in Overweight and Obese Individuals.

Henagan TM, Stewart LK, Forney LA, Sparks LM, Johannsen N, Church TS - PPAR Res (2014)

Bottom Line: We report in this paper that skeletal muscle PGC1α  -1 nucleosome (-1N) position is associated with splice variant NTPGC1α but not FLPGC1α expression.UP showed an increase in body fat percentage and serum total and LDL cholesterol.These findings suggest that the -1N may be a potential epigenetic regulator of NTPGC1α splice variant expression, and -1N position and NTPGC1α variant expression in skeletal muscle are linked to CVD risk.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition Science, Purdue University, 700 W. State Street, West Lafayette, IN 47907, USA.

ABSTRACT
PGC1α, a transcriptional coactivator, interacts with PPARs and others to regulate skeletal muscle metabolism. PGC1α undergoes splicing to produce several mRNA variants, with the NTPGC1α variant having a similar biological function to the full length PGC1α (FLPGC1α). CVD is associated with obesity and T2D and a lower percentage of type 1 oxidative fibers and impaired mitochondrial function in skeletal muscle, characteristics determined by PGC1α expression. PGC1α expression is epigenetically regulated in skeletal muscle to determine mitochondrial adaptations, and epigenetic modifications may regulate mRNA splicing. We report in this paper that skeletal muscle PGC1α  -1 nucleosome (-1N) position is associated with splice variant NTPGC1α but not FLPGC1α expression. Division of participants based on the -1N position revealed that those individuals with a -1N phased further upstream from the transcriptional start site (UP) expressed lower levels of NTPGC1α than those with the -1N more proximal to TSS (DN). UP showed an increase in body fat percentage and serum total and LDL cholesterol. These findings suggest that the -1N may be a potential epigenetic regulator of NTPGC1α splice variant expression, and -1N position and NTPGC1α variant expression in skeletal muscle are linked to CVD risk. This trial is registered with clinicaltrials.gov, identifier NCT00458133.

No MeSH data available.


Related in: MedlinePlus

PGC1α −1 nucleosome position. (a) Scanning qPCR was performed using four overlapping primer pairs targeted to the PGC1α promoter region from approximately the −800 nt to the −100 nt and depicted in the schematic. (b) Nucleosome positions were determined based on densitometry results and plotted as a line graph for each individual. All participants showed similar amplification with primer pairs 1 and 2, depicted as an upstream nucleosome (gray). Similar amplification was also seen with primer pair 3 but not with primer pair 4. This amplification pattern is depicted as a phased −1N positioned between −170 nt and −440 nt (white and black) below the line graph. Based on the phased −1N position, participants were divided into two experimental groups shown on the right: upstream (UP, black) and downstream (DN, white), and densitometry results for each group are shown as mean ± SEM in the bar graphs. −1N for UP and DN is depicted beneath each bar graph. All nucleosome positions are depicted relative to the transcriptional start site (TSS).
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fig1: PGC1α −1 nucleosome position. (a) Scanning qPCR was performed using four overlapping primer pairs targeted to the PGC1α promoter region from approximately the −800 nt to the −100 nt and depicted in the schematic. (b) Nucleosome positions were determined based on densitometry results and plotted as a line graph for each individual. All participants showed similar amplification with primer pairs 1 and 2, depicted as an upstream nucleosome (gray). Similar amplification was also seen with primer pair 3 but not with primer pair 4. This amplification pattern is depicted as a phased −1N positioned between −170 nt and −440 nt (white and black) below the line graph. Based on the phased −1N position, participants were divided into two experimental groups shown on the right: upstream (UP, black) and downstream (DN, white), and densitometry results for each group are shown as mean ± SEM in the bar graphs. −1N for UP and DN is depicted beneath each bar graph. All nucleosome positions are depicted relative to the transcriptional start site (TSS).

Mentions: Scanning qPCR was performed as previously described [16, 17]. Overlapping primers (sequences presented in Table 1) were designed to cover the PGC1α gene promoter region, ranging from ~−800 nucleotide (nt) to the −100 nt (Figure 1). PCR products for both mononucleosomal and genomic DNA samples were run on a 1.5% agarose gel and visualized on a Molecular Imager Gel Doc XR (Biorad, Hercules, CA). Densitometry was performed using MacBiophotonics ImageJ (Bethesda, MD), with mononucleosomal band intensity being divided by the intensity of the corresponding input genomic DNA.


PGC1α -1 Nucleosome Position and Splice Variant Expression and Cardiovascular Disease Risk in Overweight and Obese Individuals.

Henagan TM, Stewart LK, Forney LA, Sparks LM, Johannsen N, Church TS - PPAR Res (2014)

PGC1α −1 nucleosome position. (a) Scanning qPCR was performed using four overlapping primer pairs targeted to the PGC1α promoter region from approximately the −800 nt to the −100 nt and depicted in the schematic. (b) Nucleosome positions were determined based on densitometry results and plotted as a line graph for each individual. All participants showed similar amplification with primer pairs 1 and 2, depicted as an upstream nucleosome (gray). Similar amplification was also seen with primer pair 3 but not with primer pair 4. This amplification pattern is depicted as a phased −1N positioned between −170 nt and −440 nt (white and black) below the line graph. Based on the phased −1N position, participants were divided into two experimental groups shown on the right: upstream (UP, black) and downstream (DN, white), and densitometry results for each group are shown as mean ± SEM in the bar graphs. −1N for UP and DN is depicted beneath each bar graph. All nucleosome positions are depicted relative to the transcriptional start site (TSS).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4295622&req=5

fig1: PGC1α −1 nucleosome position. (a) Scanning qPCR was performed using four overlapping primer pairs targeted to the PGC1α promoter region from approximately the −800 nt to the −100 nt and depicted in the schematic. (b) Nucleosome positions were determined based on densitometry results and plotted as a line graph for each individual. All participants showed similar amplification with primer pairs 1 and 2, depicted as an upstream nucleosome (gray). Similar amplification was also seen with primer pair 3 but not with primer pair 4. This amplification pattern is depicted as a phased −1N positioned between −170 nt and −440 nt (white and black) below the line graph. Based on the phased −1N position, participants were divided into two experimental groups shown on the right: upstream (UP, black) and downstream (DN, white), and densitometry results for each group are shown as mean ± SEM in the bar graphs. −1N for UP and DN is depicted beneath each bar graph. All nucleosome positions are depicted relative to the transcriptional start site (TSS).
Mentions: Scanning qPCR was performed as previously described [16, 17]. Overlapping primers (sequences presented in Table 1) were designed to cover the PGC1α gene promoter region, ranging from ~−800 nucleotide (nt) to the −100 nt (Figure 1). PCR products for both mononucleosomal and genomic DNA samples were run on a 1.5% agarose gel and visualized on a Molecular Imager Gel Doc XR (Biorad, Hercules, CA). Densitometry was performed using MacBiophotonics ImageJ (Bethesda, MD), with mononucleosomal band intensity being divided by the intensity of the corresponding input genomic DNA.

Bottom Line: We report in this paper that skeletal muscle PGC1α  -1 nucleosome (-1N) position is associated with splice variant NTPGC1α but not FLPGC1α expression.UP showed an increase in body fat percentage and serum total and LDL cholesterol.These findings suggest that the -1N may be a potential epigenetic regulator of NTPGC1α splice variant expression, and -1N position and NTPGC1α variant expression in skeletal muscle are linked to CVD risk.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition Science, Purdue University, 700 W. State Street, West Lafayette, IN 47907, USA.

ABSTRACT
PGC1α, a transcriptional coactivator, interacts with PPARs and others to regulate skeletal muscle metabolism. PGC1α undergoes splicing to produce several mRNA variants, with the NTPGC1α variant having a similar biological function to the full length PGC1α (FLPGC1α). CVD is associated with obesity and T2D and a lower percentage of type 1 oxidative fibers and impaired mitochondrial function in skeletal muscle, characteristics determined by PGC1α expression. PGC1α expression is epigenetically regulated in skeletal muscle to determine mitochondrial adaptations, and epigenetic modifications may regulate mRNA splicing. We report in this paper that skeletal muscle PGC1α  -1 nucleosome (-1N) position is associated with splice variant NTPGC1α but not FLPGC1α expression. Division of participants based on the -1N position revealed that those individuals with a -1N phased further upstream from the transcriptional start site (UP) expressed lower levels of NTPGC1α than those with the -1N more proximal to TSS (DN). UP showed an increase in body fat percentage and serum total and LDL cholesterol. These findings suggest that the -1N may be a potential epigenetic regulator of NTPGC1α splice variant expression, and -1N position and NTPGC1α variant expression in skeletal muscle are linked to CVD risk. This trial is registered with clinicaltrials.gov, identifier NCT00458133.

No MeSH data available.


Related in: MedlinePlus