scholarly journals Reduced Liver-Specific PGC1a Increases Susceptibility for Short-Term Diet-Induced Weight Gain in Male Mice

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2596
Author(s):  
E. Matthew Morris ◽  
Roberto D. Noland ◽  
Michael E. Ponte ◽  
Michelle L. Montonye ◽  
Julie A. Christianson ◽  
...  

The central integration of peripheral neural signals is one mechanism by which systemic energy homeostasis is regulated. Previously, increased acute food intake following the chemical reduction of hepatic fatty acid oxidation and ATP levels was prevented by common hepatic branch vagotomy (HBV). However, possible offsite actions of the chemical compounds confound the precise role of liver energy metabolism. Herein, we used a hepatocyte PGC1a heterozygous (LPGC1a) mouse model, with associated reductions in mitochondrial fatty acid oxidation and respiratory capacity, to assess the role of liver energy metabolism in systemic energy homeostasis. LPGC1a male, but not female, mice had a 70% greater high-fat/high-sucrose (HFHS) diet-induced weight gain compared to wildtype (WT) mice (p < 0.05). The greater weight gain was associated with altered feeding behavior and lower activity energy expenditure during the HFHS diet in LPGC1a males. WT and LPGC1a mice underwent sham surgery or HBV to assess whether vagal signaling was involved in the HFHS-induced weight gain of male LPGC1a mice. HBV increased HFHS-induced weight gain (85%, p < 0.05) in male WT mice, but not LPGC1a mice. These data demonstrate a sex-specific role of reduced liver energy metabolism in acute diet-induced weight gain, and the need for a more nuanced assessment of the role of vagal signaling in short-term diet-induced weight gain.

2020 ◽  
Author(s):  
E. Matthew Morris ◽  
Roberto D. Noland ◽  
Michael E. Ponte ◽  
Michelle L. Montonye ◽  
Julie A. Christianson ◽  
...  

AbstractCentral integration of peripheral neural signals is one mechanism by which systemic energy homeostasis is regulated. Previous work described increased acute food intake following chemical reduction of hepatic fatty acid oxidation and ATP levels, which was prevented by common hepatic branch vagotomy (HBV). However, possible offsite actions of the chemical compounds confound the precise role of liver energy metabolism. Herein, we used a liver-specific PGC1a heterozygous (LPGC1a) mouse model, with associated reductions in mitochondrial fatty acid oxidation and respiratory capacity, to assess the role of liver energy metabolism in systemic energy homeostasis. LPGC1a male mice have 70% greater high-fat/high-sucrose (HFHS) diet-induced weight gain and 35% greater positive energy balance compared to wildtype (WT) (p<0.05). The greater energy balance was associated with altered feeding behavior and lower activity energy expenditure during HFHS in LPGC1a males. Importantly, no differences in HFHS-induced weight gain or energy metabolism was observed between female WT and LPGC1a mice. WT and LPGC1a mice underwent sham or HBV to assess whether vagal signaling was involved in HFHS-induced weight gain of male LPGC1a mice. HBV increased HFHS-induced weight gain (85%, p<0.05) in male WT, but not LPGC1a mice. As above, sham LPGC1a males gain 70% more weight during short-term HFHS feeding than sham WT (p<0.05). These data demonstrate a sexspecific role of reduced liver energy metabolism in acute diet-induced weight gain, and the need of more nuanced assessment of the role of vagal signaling in short-term diet-induced weight gain.Key Points SummaryReduced liver PGC1a expression results in reduced mitochondrial fatty acid oxidation and respiratory capacity in male mice.Male mice with reduced liver PGC1a expression (LPGC1a) demonstrate greater short-term high-fat/high-sucrose diet-induced weight gain compared to wildtype.Greater positive energy balance during HFHS feeding in male LPGC1a mice is associated with altered food intake patterns and reduced activity energy expenditure.Female LPGC1a mice do not have differences in short-term HFHS-induced body weight gain or energy metabolism compared to wildtype.Disruption of vagal signaling through common hepatic branch vagotomy increases short-term HFHS-induced weight gain in male wildtype mice, but does not alter male LPGC1a weight gain.


2009 ◽  
Vol 296 (3) ◽  
pp. E497-E502 ◽  
Author(s):  
A. Lombardi ◽  
P. de Lange ◽  
E. Silvestri ◽  
R. A. Busiello ◽  
A. Lanni ◽  
...  

Triiodothyronine regulates energy metabolism and thermogenesis. Among triiodothyronine derivatives, 3,5-diiodo-l-thyronine (T2) has been shown to exert marked effects on energy metabolism by acting mainly at the mitochondrial level. Here we investigated the capacity of T2 to affect both skeletal muscle mitochondrial substrate oxidation and thermogenesis within 1 h after its injection into hypothyroid rats. Administration of T2 induced an increase in mitochondrial oxidation when palmitoyl-CoA (+104%), palmitoylcarnitine (+80%), or succinate (+30%) was used as substrate, but it had no effect when pyruvate was used. T2 was able to 1) activate the AMPK-ACC-malonyl-CoA metabolic signaling pathway known to direct lipid partitioning toward oxidation and 2) increase the importing of fatty acids into the mitochondrion. These results suggest that T2 stimulates mitochondrial fatty acid oxidation by activating several metabolic pathways, such as the fatty acid import/β-oxidation cycle/FADH2-linked respiratory pathways, where fatty acids are imported. T2 also enhanced skeletal muscle mitochondrial thermogenesis by activating pathways involved in the dissipation of the proton-motive force not associated with ATP synthesis (“proton leak”), the effect being dependent on the presence of free fatty acids inside mitochondria. We conclude that skeletal muscle is a target for T2, and we propose that, by activating processes able to enhance mitochondrial fatty acid oxidation and thermogenesis, T2 could play a role in protecting skeletal muscle against excessive intramyocellular lipid storage, possibly allowing it to avoid functional disorders.


Aging Cell ◽  
2013 ◽  
Vol 12 (3) ◽  
pp. 415-425 ◽  
Author(s):  
Dan Nguyen ◽  
Susan L. Samson ◽  
Vasumathi T. Reddy ◽  
Erica V. Gonzalez ◽  
Rajagopal V. Sekhar

2020 ◽  
Author(s):  
◽  
Rory P. Cunningham

Whole body loss of endothelial nitric oxide synthase (eNOS) worsens hepatic mitochondrial function and exacerbates nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) development and progression. However, the precise role of eNOS in hepatocytes in the contribution to NAFLD has not been established. Here, we use gain- and loss- of-function approaches including a hepatocyte-specific eNOS knockout mouse model (eNOShep-/-), and lifestyle interventions (diet and exercise), to investigate the role of hepatocellular eNOS in NAFLD/NASH development and hepatic mitochondrial adaptations to exercise. Ablation of hepatocellular eNOS via genetic and viral knockout exacerbated hepatic steatosis and inflammation, decreased hepatic mitochondrial fatty acid oxidation and respiration, and impaired mitophagy. Conversely, overexpressing hepatocellular eNOS via viral approaches increased hepatocyte respiration, markers of mitophagy, while attenuating NASH progression. Interestingly, these detriments were not rescued by BNIP3 overexpression or nitric oxide (NO) donors in eNOS deficient hepatocytes. In addition, elevated H2O2 emission and hepatic steatosis in eNOShep-/- mice was completely ablated with 10 weeks of voluntary wheel running exercise. Interestingly, eNOShep-/- male mice had a blunted exercise-induced increase in hepatic fatty acid oxidation. eNOShep-/- mice also had impaired markers of energy sensing ability of the cell and attenuated activation of the autophagy initiating factor ULK1. While mitochondrial respiration and markers of mitochondrial content were not increased with exercise, female mice showed markers of mitochondrial biogenesis. Collectively, these data uncover the important and novel role of hepatocellular eNOS in exercise-induced hepatic mitochondrial adaptations, and help to further the understanding behind the mechanistic role of eNOS in NAFLD development.


Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 767 ◽  
Author(s):  
Kristen E. Boyle ◽  
Margaret J. Magill-Collins ◽  
Sean A. Newsom ◽  
Rachel C. Janssen ◽  
Jacob E. Friedman

Overweight and obesity accompanies up to 70% of pregnancies and is a strong risk factor for offspring metabolic disease. Maternal obesity-associated inflammation and lipid profile are hypothesized as important contributors to excess offspring liver and skeletal muscle lipid deposition and oxidative stress. Here, we tested whether dams expressing the fat-1 transgene, which endogenously converts omega-6 (n-6) to omega-3 (n-3) polyunsaturated fatty acid, could protect wild-type (WT) offspring against high-fat diet induced weight gain, oxidative stress, and disrupted mitochondrial fatty acid oxidation. Despite similar body mass at weaning, offspring from fat-1 high-fat-fed dams gained less weight compared with offspring from WT high-fat-fed dams. In particular, WT males from fat-1 high-fat-fed dams were protected from post-weaning high-fat diet induced weight gain, reduced fatty acid oxidation, or excess oxidative stress compared with offspring of WT high-fat-fed dams. Adult offspring of WT high-fat-fed dams exhibited greater skeletal muscle triglycerides and reduced skeletal muscle antioxidant defense and redox balance compared with offspring of WT dams on control diet. Fat-1 offspring were protected from the reduced fatty acid oxidation and excess oxidative stress observed in offspring of WT high-fat-fed dams. These results indicate that a maternal fat-1 transgene has protective effects against offspring liver and skeletal muscle lipotoxicity resulting from a maternal high-fat diet, particularly in males. Altering maternal fatty acid composition, without changing maternal dietary composition or weight gain with high-fat feeding, may highlight important strategies for n-3-based prevention of developmental programming of obesity and its complications.


2009 ◽  
Vol 50 (9) ◽  
pp. 1789-1799 ◽  
Author(s):  
David Sebastián ◽  
Maria Guitart ◽  
Celia García-Martínez ◽  
Caroline Mauvezin ◽  
Josep M. Orellana-Gavaldà ◽  
...  

2019 ◽  
Author(s):  
Helena Urquijo ◽  
Emma N Panting ◽  
Roderick N Carter ◽  
Emma J Agnew ◽  
Caitlin S Wyrwoll ◽  
...  

1991 ◽  
Vol 266 (34) ◽  
pp. 22932-22938
Author(s):  
R.S. Kler ◽  
S. Jackson ◽  
K. Bartlett ◽  
L.A. Bindoff ◽  
S. Eaton ◽  
...  

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