miun.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Upregulation of nicotinamide n-methyltransferase in skeletal muscle following prolongedexercise and caloric restriction
University of Las Palmas, Spain.
University of Las Palmas, Spain.
University of Las Palmas, Spain.
University of Las Palmas, Spain.
Show others and affiliations
2017 (English)In: 22nd Annual Congress of the European College of Sport Science / [ed] Ferrauti, A., Platen, P., Grimminger-Seidensticker, E., Jaitner, T.,, Cologne, Germany: DTP Publishing, 2017, p. 186-, article id MO-PM03Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Introduction

Expression of Nicotinamide (NA) N-methyltransferase (NNMT), the enzyme responsible for the methylation of NA to methylnicotinamide (MNA), is reduced in obese and diabetic mice. In rodent liver, NNMT activity and plasma MNA levels are increased after 90min of swimming.

NNMT knockdown in mice white adipose tissue increases energy expenditure, suggesting a protective role against diet-induced obesity and type-2 diabetes. The role that NNMT plays in human metabolism remains unknown. Thus, the aims of the study were 1) to determine in human skeletal muscle (sm) whether NNMT is upregulated by prolonged exercise and 2) to ascertain whether the expression of NNMT in sm is influenced by severe energy deficit.

Methods

Fifteen overweight men underwent to 4 days of caloric restriction (CR) (0.8 g/kg BW/day) in combination with prolonged exercise (PE) (8h walking + 45min single-arm cranking/day). Three sm biopsies (exercised/non exercised arm and one leg) were obtained before (PRE), after (PE+CR) and following 3 days of control diet (isoenergetic) and reduced exercise (CD) to measure the expression of key metabolic genes (e.g. PDK4, CPT2, PFKFB3, NNMT) (microarray), NNMT protein expression (WB) and circulating plasma MNA levels (LC-MS). Maximal fat oxidation (MFO) (indirect calorimetry) and body composition (DEXA) were measured. ANOVA repeated-measures was used.

Results

During PE+CR the energy deficit was 5000 kcal/d reducing fat mass by 2.8 (PE+CR) and 3.8 kg (CD). MFO was increased. CPT2, PDK4, PFKFB3 genes (CHO-to-fat metabolic shift) were differentially expressed (FDR<5%) in at least one sm. Compared to PRE, after CD, NNMT gene expression was upregulated in all sm (~3-5 fold). Protein NNMT increased ~13-fold (p<0.001), ~9-fold (p<0.01) and ~5-fold (p<0.001) for non-exercised and exercised arm (45min/day) and leg (8h/day), respectively. Circulating levels of MNA were augmented two-fold. The increase in NNMT expression from PRE to CD was associated with the increase in MFO (r=0.37, p=0.01,n=45).

Discussion

This findings reveal that NNMT is upregulated in human sm in response to a severe energy deficit, with a simultaneous increase of MNA plasma levels. However, this response was attenuated in the exercised sm. NNMT may have a role in facilitating fat oxidation. Caloric restriction elicits increased sirtuins expression and activity, coupled with the NAD+ breakdown into NA. Overexpression of NNMT probably prevents accumulation of NA, which would otherwise inhibit the sirtuins. Our data suggest sm as a plausible source of MNA, which may act as a myokine with a role in the adaptation to starvation.

Place, publisher, year, edition, pages
Cologne, Germany: DTP Publishing, 2017. p. 186-, article id MO-PM03
National Category
Physiology Sport and Fitness Sciences
Identifiers
URN: urn:nbn:se:miun:diva-32664ISBN: 978-3-9818414-0-4 (print)OAI: oai:DiVA.org:miun-32664DiVA: diva2:1173248
Conference
22nd Annual Congress of the European College of Sport Science, Metropolis Ruhr, July 5-8, 2017
Available from: 2018-01-11 Created: 2018-01-11 Last updated: 2018-01-15Bibliographically approved

Open Access in DiVA

No full text in DiVA

Authority records BETA

Holmberg, Hans-Christer

Search in DiVA

By author/editor
Holmberg, Hans-Christer
By organisation
Department of Health Sciences
PhysiologySport and Fitness Sciences

Search outside of DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 25 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf