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Effects of obesity on sGCβ1 mediated signaling in white adipose tissue

Background

Obesity has reached pandemic proportions with 1.9 billion overweight adults; 600 million of whom are obese [1]. It has been shown that stimulating cyclic 3’-5’ guanosine monophosphate (cGMP) signaling is able to promote adipose tissue homeostasis in obese mice [2]. Conversely, genetic depletion of cGMP dependent protein kinase 1 (PKG1), causes hepatic inflammation and fasting hyperglycemia in mice [3]. Furthermore, cGMP signaling is essential for differentiation of preadipocytes to mature adipocytes in vitro [4, 5]. PKG1 activation blocks RhoA mediated inhibition of insulin receptor substrate 1 in adipocytes in vitro [4, 5], thus maintaining insulin sensitivity. The status of cGMP signaling cascade in adipose tissue under obese conditions is not yet fully understood. Here, we examine the functional status of cGMP signaling in white adipose tissue (WAT) of lean and obese mice.

Materials and methods

For the purposes of this study, WAT from genetically (ob/ob) and diet induced obese (DIO) mice was compared to their respective lean controls. Western blot (WB) and qPCR analyses were preformed to ascertain expression levels of cGMP signaling cascade components: soluble guanylyl cyclase β1 subunit (sGCβ1) and PKG1. Tissue cGMP levels were also measured as an indicator of sGC function.

Results

Protein expression of sGCβ1 was reduced by 50% in WAT of obese mice as compared to their respective lean controls. Similarly, sGCβ1 mRNA was also decreased by approximately 50%. In line, cGMP production induced by NO donor (10µM S-Nitroso-N-acetyl-DL-penicillamine) stimulation was a third in WAT of ob/ob mice compared to ob/+. PKG1 protein and mRNA expression was halved in the WAT of obese mice (both ob/ob and DIO) as compared to controls.

Conclusion

Results thus far indicate that key components of the cGMP cascade (sGCβ1 and PKG1) are down-regulated in WAT of obese mice. As a consequence of sGCβ1 repression, cGMP production is also dented. Considering the importance of cGMP signaling in maintaining adipocyte function and tissue homeostasis [25], disruption of the cascade in WAT could result in the co-morbidities associated with obesity, like hyperlipidemia and insulin resistance. Hampered preadipocyte differentiation due to cGMP signaling dysfunction could result in incapacitated adipocytes leading to ectopic lipid deposition, exacerbating tissue homeostasis. Retardation of the cGMP cascade could result from ER stress and/ or inflammation, which are escalated in obesity [6, 7]. It is therefore, essential to delineate the causes for cGMP cascade disruption in this context. Furthermore, targeting the cGMP cascade could help normalize adipocyte function and tissue homeostasis in obese WAT.

References

  1. 1.

    [http://www.who.int/mediacentre/factsheets/fs311/en/]

  2. 2.

    Handa P, Tateya S, Rizzo NO, Cheng AM, Morgan-Stevenson V, Han CY, et al: Reduced vascular nitric oxide-cGMP signaling contributes to adipose tissue inflammation during high-fat feeding. Arterioscler Thromb Vasc Biol. 2011, 31 (12): 2827-2835. 10.1161/ATVBAHA.111.236554.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  3. 3.

    Lutz SZ, Hennige AM, Feil S, Peter A, Gerling A, Machann J, et al: Genetic ablation of cGMP-dependent protein kinase type I causes liver inflammation and fasting hyperglycemia. Diabetes. 2011, 60 (5): 1566-1576. 10.2337/db10-0760.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  4. 4.

    Haas B, Mayer P, Jennissen K, Scholz D, Berriel Diaz M, Bloch W, Herzig S, Fässler R, Pfeifer A: Protein kinase G controls brown fat cell differentiation and mitochondrial biogenesis. Sci Signal. 2009, 2 (99): ra78-

    Article  PubMed  Google Scholar 

  5. 5.

    Mitschke MM, Hoffmann LS, Gnad T, Scholz D, Kruithoff K, Mayer P, Haas B, Sassmann A, Pfeifer A, Kilic A: Increased cGMP promotes healthy expansion and browning of white adipose tissue. FASEB J. 2013, 27 (4): 1621-1630. 10.1096/fj.12-221580.

    CAS  Article  PubMed  Google Scholar 

  6. 6.

    Hotamisligil GS: Inflammation and endoplasmic reticulum stress in obesity and diabetes. Int J Obes (Lond). 2008, 32 (Suppl 7): S52-S54.

    CAS  Article  Google Scholar 

  7. 7.

    Kawasaki N1, Asada R, Saito A, Kanemoto S, Imaizumi K: Obesity-induced endoplasmic reticulum stress causes chronic inflammation in adipose tissue. Sci Rep. 2012, 2: 799-

    Article  PubMed  PubMed Central  Google Scholar 

Download references

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Correspondence to Abhishek Sanyal.

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This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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Sanyal, A., Hoffmann, L.S., Etzrodt, J. et al. Effects of obesity on sGCβ1 mediated signaling in white adipose tissue. BMC Pharmacol Toxicol 16, A83 (2015). https://doi.org/10.1186/2050-6511-16-S1-A83

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Keywords

  • White Adipose Tissue
  • Obese Mouse
  • Tissue Homeostasis
  • Diet Induce Obese
  • cGMP Production