Role of Stearoyl-CoA Desaturase-1 in Skin Integrity and Whole Body Energy Balance

Obesity is becoming a pandemic, and its prevalence is still increasing. Considering that obesity increases the risk of developing cardiometabolic diseases, research efforts are focusing on new ways to combat obesity. Brown adipose tissue (BAT) has emerged as a possible target to achieve this for its functional role in energy expenditure by means of increasing thermogenesis. An important metabolic sensor and regulator of whole-body energy balance is AMP-activated protein kinase (AMPK), and its role in energy metabolism is evident. This review highlights the mechanisms of BAT activation and investigates how AMPK can be used as a target for BAT activation. We review compounds and other factors that are able to activate AMPK and further discuss the therapeutic use of AMPK in BAT activation. Extensive research shows that AMPK can be activated by a number of different kinases, such as LKB1, CaMKK, but also small molecules, hormones, and metabolic stresses. AMPK is able to activate BAT by inducing adipogenesis, maintaining mitochondrial homeostasis and inducing browning in white adipose tissue. We conclude that, despite encouraging results, many uncertainties should be clarified before AMPK can be posed as a target for anti-obesity treatment via BAT activation.

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Role of AMPK in mammals reproduction: Specific controls and whole-body energy sensing

Comptes Rendus Biologies ◽

10.1016/j.crvi.2018.10.003 ◽

2019 ◽

Vol 342 (1-2) ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Thi Mong Diep Nguyen

Keyword(s):

Whole Body ◽

Energy Sensing ◽

Body Energy

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Uncoupling of sarcoendoplasmic reticulum calcium ATPase pump activity by sarcolipin as the basis for muscle non-shivering thermogenesis

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2019.0135 ◽

2020 ◽

Vol 375 (1793) ◽

pp. 20190135 ◽

Cited By ~ 3

Author(s):

Naresh C. Bal ◽

Muthu Periasamy

Keyword(s):

Energy Homeostasis ◽

Atp Hydrolysis ◽

Calcium Atpase ◽

Whole Body ◽

Signalling Molecule ◽

Brown Adipose ◽

Pump Activity ◽

Body Energy ◽

Shivering Thermogenesis

Thermogenesis in endotherms relies on both shivering and non-shivering thermogenesis (NST). The role of brown adipose tissue (BAT) in NST is well recognized, but the role of muscle-based NST has been contested. However, recent studies have provided substantial evidence for the importance of muscle-based NST in mammals. This review focuses primarily on the role of sarcoplasmic reticulum (SR) Ca 2+ -cycling in muscle NST; specifically, it will discuss recent data showing how uncoupling of sarcoendoplasmic reticulum calcium ATPase (SERCA) (inhibition of Ca 2+ transport but not ATP hydrolysis) by sarcolipin (SLN) results in futile SERCA pump activity, increased ATP hydrolysis and heat production contributing to muscle NST. It will also critically examine how activation of muscle NST can be an important factor in regulating metabolic rate and whole-body energy homeostasis. In this regard, SLN has emerged as a powerful signalling molecule to promote mitochondrial biogenesis and oxidative metabolism in muscle. Furthermore, we will discuss the functional interplay between BAT and muscle, especially with respect to how reduced BAT function in mammals could be compensated by muscle-based NST. Based on the existing data, we argue that SLN-mediated thermogenesis is an integral part of muscle NST and that muscle NST potentially contributed to the evolution of endothermy within the vertebrate clade. This article is part of the theme issue ‘Vertebrate palaeophysiology’.

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TLR4-interactor with leucine-rich repeats (TRIL) is involved in diet-induced hypothalamic inflammation

Scientific Reports ◽

10.1038/s41598-021-97291-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Alexandre Moura-Assis ◽

Pedro A. S. Nogueira ◽

Jose C. de-Lima-Junior ◽

Fernando M. Simabuco ◽

Joana M. Gaspar ◽

...

Keyword(s):

Dietary Fats ◽

Whole Body ◽

Metabolic Dysfunction ◽

Diet Induced Obesity ◽

Hypothalamic Inflammation ◽

Novel Target ◽

Tlr4 Activation ◽

Leucine Rich Repeats ◽

Body Energy

AbstractObesity and high-fat diet (HFD) consumption result in hypothalamic inflammation and metabolic dysfunction. While the TLR4 activation by dietary fats is a well-characterized pathway involved in the neuronal and glial inflammation, the role of its accessory proteins in diet-induced hypothalamic inflammation remains unknown. Here, we demonstrate that the knockdown of TLR4-interactor with leucine-rich repeats (Tril), a functional component of TLR4, resulted in reduced hypothalamic inflammation, increased whole-body energy expenditure, improved the systemic glucose tolerance and protection from diet-induced obesity. The POMC-specific knockdown of Tril resulted in decreased body fat, decreased white adipose tissue inflammation and a trend toward increased leptin signaling in POMC neurons. Thus, Tril was identified as a new component of the complex mechanisms that promote hypothalamic dysfunction in experimental obesity and its inhibition in the hypothalamus may represent a novel target for obesity treatment.

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Effect of fescue toxicosis on whole body energy and nitrogen balance, in situ degradation and ruminal passage rates in Holstein steers

Animal Production Science ◽

10.1071/an14037 ◽

2015 ◽

Vol 55 (8) ◽

pp. 988 ◽

Cited By ~ 5

Author(s):

A. F. Koontz ◽

D. H. Kim ◽

K. R. McLeod ◽

J. L. Klotz ◽

D. L. Harmon

Keyword(s):

Energy Balance ◽

Whole Body ◽

Fescue Toxicosis ◽

Design Experiment ◽

Feeding Level ◽

Structure Factors ◽

In Situ Degradation ◽

Body Energy ◽

Treatment Structure

This study was designed to examine alteration of ruminal kinetics, as well as N and energy balance during fescue toxicosis. Six ruminally cannulated Holstein steers (bodyweight (BW) = 217 ± 7 kg) were weight matched into pairs and pair fed throughout a crossover design experiment with a 2×2 factorial treatment structure. Factors were endophyte (infected, E+ vs. uninfected, E−) and feeding level (1100 (L) or 1800 (H) kJ/kG BW.75). During each period, after 8 days of feeding level adaptation, animals were ruminally dosed twice daily with ground fescue seed for the remainder of the period. One steer per pair was dosed with ground endophyte infected fescue seed (E+), the other with ground endophyte free fescue seed. In situ degradation of ground alfalfa was determined on Days 13–16. Total faecal and urinary collections were performed on Days 17–21, with animals placed into indirect calorimetry head-boxes during Days 20 and 21. Heat production (HP) was calculated using the Brower equation. Retained energy (RE) was calculated as intakeE – (faecalE + urinaryE + gaseousE + HP). Liquid and particulate passage rates were evaluated using Cr:EDTA and iADF respectively on Days 22 and 23. There was no difference (P > 0.9) in dry matter intake (DMI)/kg.75 between endophyte treatments, and DMI/kg.75 was different (P < 0.01) between H and L intake by design. Animals on H feeding had higher (P < 0.01) water, N and energy intakes. Energy and N excretion, as well as retained DE, ME, RE, and HP were higher (P < 0.03) for H versus L. There was no difference in retained N, DE, ME, or HP (P > 0.15) between endophyte treatments. Neither rate nor extent of in situ degradation was altered by intake level or endophyte treatment (P > 0.3). DM percentage and DM weight of rumen contents were increased (P < 0.01) by E+ dosing. Particulate passage increased (P = 0.0002) during H intake and decreased (P = 0.02) with E+ dosing. Ruminal liquid passage decreased (P < 0.03) with H feeding, while liquid flow rate tended to be reduced (P < 0.14) with E+ dosing. Total VFA concentration increased with both H feeding (P < 0.01) and E+ dosing (P < 0.0001). Despite these differences, the N and energy balance data indicate that the reductions in weight gain and productivity seen during fescue toxicosis are primarily due to reduced intake.

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