Limits...
Maternal influence of prolyl endopeptidase on fat mass of adult progeny.

Warden CH, Fisler JS, Espinal G, Graham J, Havel PJ, Perroud B - Int J Obes (Lond) (2009)

Bottom Line: There were no genotype effects on BW or AI in males or females on either diet.Experiment 2-In contrast, reciprocal crosses of heterozygous males or females with WT B6 revealed highly significant parent of origin effects on all traits except body length.Heterozygosity for PREP GT results in highly significant maternal effects, whereas homozygosity for the PREP(gt/gt) mutation has a much more limited direct effect.

View Article: PubMed Central - PubMed

Affiliation: Rowe Program in Genetics, University of California, Davis, CA 95616, USA. chwarden@ucdavis.edu

ABSTRACT

Background: Maternal genotype has lifetime effects on progeny, but few specific genes, and no proteases, are known to underlie maternal effects. Prolyl endopeptidase (PREP) is a serine protease with putative substrates that regulate appetite or milk production.

Objective: To test effects of PREP on obesity phenotypes in mice.

Design: Mice with a gene trap (GT) of PREP (PREP(gt/gt)) on the C57BL/6J (B6) background were generated. Minimal PREP protein was detected by western blot. In Experiment 1, direct effects of PREP were measured in littermate mice derived from intercrosses of heterozygotes (PREP(WT/gt)). In Experiment 2, maternal effects of PREP were measured in reciprocal crosses of heterozygous (PREP(WT/gt)) and wild-type (WT) (PREP(WT/WT)) males and females. DIETS: Mice were fed either low-fat (LF, Experiments 1 and 2) or high-fat (HF, Experiment 1) defined diets.

Measurements: Adiposity index (AI) was calculated from body weight (BW) and weights of four fat depots measured in 120-day-old mice. Fasting plasma glucose, insulin and leptin were measured. In vivo plasma alpha-MSH levels were measured by targeted quantitative peptidomics.

Results: Experiment 1-In intercross mice, there were significant diet effects, but few genotype effects. There were no genotype effects on BW or AI in males or females on either diet. Experiment 2-In contrast, reciprocal crosses of heterozygous males or females with WT B6 revealed highly significant parent of origin effects on all traits except body length. Progeny (WT and heterozygous genotypes and both sexes) born to female PREP(WT/gt) heterozygotes had fat pads that weighed as much as -twofold more at 120 days old than progeny born to male heterozygotes.

Conclusion: Heterozygosity for PREP GT results in highly significant maternal effects, whereas homozygosity for the PREP(gt/gt) mutation has a much more limited direct effect.

Show MeSH

Related in: MedlinePlus

α-MSH plasma level determined by quantitative targeted proteomics. Average of MRM transitions combined peak areas shows a genotype effect. There is 1.5 fold more α-MSH in the plasma of wild-type mice (N=10) than in homozygous gene-trap mice (N=9) (Student t-test p-value = 0.0016).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2743752&req=5

Figure 4: α-MSH plasma level determined by quantitative targeted proteomics. Average of MRM transitions combined peak areas shows a genotype effect. There is 1.5 fold more α-MSH in the plasma of wild-type mice (N=10) than in homozygous gene-trap mice (N=9) (Student t-test p-value = 0.0016).

Mentions: Using targeted quantitative proteomics, we measured the active, N-acetylated and C-amidated α-MSH from the plasma of PREPgt/gt mice and wild-type littermates. First, using MSMS on α-MSH standard, we identified 5 Multiple Reaction Monitoring (MRM) transitions that we could then monitor in plasma samples. Because of the variability encountered across the biological samples, we also monitored γ-MSH, another prohormone, proopiomelanocortin (POMC) derived peptide. γ-MSH also results from the digestion of a POMC derived peptide by proprotein convertase subtilisin/kexin type 2 (Pcsk2) but it lacks a proline and thus is not a putative PREP substrate. We identified 8 MRM transitions using γ-MSH standard and then quantitated γ-MSH in multiplex, i.e. in the same MS run as α-MSH. We observed a close correlation between the two hormones for each genotype: R2=0.93 and R2=0.90 respectively for the PREPgt/gt and WT genotypes (Figure 3). When normalizing α-MSH with γ-MSH levels, we detected a statistically significant decrease (1.5 fold) of α-MSH in the plasma of PREPgt/gt mice with a one tailed Student t-test p-value = 0.0016 (Figure 4).


Maternal influence of prolyl endopeptidase on fat mass of adult progeny.

Warden CH, Fisler JS, Espinal G, Graham J, Havel PJ, Perroud B - Int J Obes (Lond) (2009)

α-MSH plasma level determined by quantitative targeted proteomics. Average of MRM transitions combined peak areas shows a genotype effect. There is 1.5 fold more α-MSH in the plasma of wild-type mice (N=10) than in homozygous gene-trap mice (N=9) (Student t-test p-value = 0.0016).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2743752&req=5

Figure 4: α-MSH plasma level determined by quantitative targeted proteomics. Average of MRM transitions combined peak areas shows a genotype effect. There is 1.5 fold more α-MSH in the plasma of wild-type mice (N=10) than in homozygous gene-trap mice (N=9) (Student t-test p-value = 0.0016).
Mentions: Using targeted quantitative proteomics, we measured the active, N-acetylated and C-amidated α-MSH from the plasma of PREPgt/gt mice and wild-type littermates. First, using MSMS on α-MSH standard, we identified 5 Multiple Reaction Monitoring (MRM) transitions that we could then monitor in plasma samples. Because of the variability encountered across the biological samples, we also monitored γ-MSH, another prohormone, proopiomelanocortin (POMC) derived peptide. γ-MSH also results from the digestion of a POMC derived peptide by proprotein convertase subtilisin/kexin type 2 (Pcsk2) but it lacks a proline and thus is not a putative PREP substrate. We identified 8 MRM transitions using γ-MSH standard and then quantitated γ-MSH in multiplex, i.e. in the same MS run as α-MSH. We observed a close correlation between the two hormones for each genotype: R2=0.93 and R2=0.90 respectively for the PREPgt/gt and WT genotypes (Figure 3). When normalizing α-MSH with γ-MSH levels, we detected a statistically significant decrease (1.5 fold) of α-MSH in the plasma of PREPgt/gt mice with a one tailed Student t-test p-value = 0.0016 (Figure 4).

Bottom Line: There were no genotype effects on BW or AI in males or females on either diet.Experiment 2-In contrast, reciprocal crosses of heterozygous males or females with WT B6 revealed highly significant parent of origin effects on all traits except body length.Heterozygosity for PREP GT results in highly significant maternal effects, whereas homozygosity for the PREP(gt/gt) mutation has a much more limited direct effect.

View Article: PubMed Central - PubMed

Affiliation: Rowe Program in Genetics, University of California, Davis, CA 95616, USA. chwarden@ucdavis.edu

ABSTRACT

Background: Maternal genotype has lifetime effects on progeny, but few specific genes, and no proteases, are known to underlie maternal effects. Prolyl endopeptidase (PREP) is a serine protease with putative substrates that regulate appetite or milk production.

Objective: To test effects of PREP on obesity phenotypes in mice.

Design: Mice with a gene trap (GT) of PREP (PREP(gt/gt)) on the C57BL/6J (B6) background were generated. Minimal PREP protein was detected by western blot. In Experiment 1, direct effects of PREP were measured in littermate mice derived from intercrosses of heterozygotes (PREP(WT/gt)). In Experiment 2, maternal effects of PREP were measured in reciprocal crosses of heterozygous (PREP(WT/gt)) and wild-type (WT) (PREP(WT/WT)) males and females. DIETS: Mice were fed either low-fat (LF, Experiments 1 and 2) or high-fat (HF, Experiment 1) defined diets.

Measurements: Adiposity index (AI) was calculated from body weight (BW) and weights of four fat depots measured in 120-day-old mice. Fasting plasma glucose, insulin and leptin were measured. In vivo plasma alpha-MSH levels were measured by targeted quantitative peptidomics.

Results: Experiment 1-In intercross mice, there were significant diet effects, but few genotype effects. There were no genotype effects on BW or AI in males or females on either diet. Experiment 2-In contrast, reciprocal crosses of heterozygous males or females with WT B6 revealed highly significant parent of origin effects on all traits except body length. Progeny (WT and heterozygous genotypes and both sexes) born to female PREP(WT/gt) heterozygotes had fat pads that weighed as much as -twofold more at 120 days old than progeny born to male heterozygotes.

Conclusion: Heterozygosity for PREP GT results in highly significant maternal effects, whereas homozygosity for the PREP(gt/gt) mutation has a much more limited direct effect.

Show MeSH
Related in: MedlinePlus