, Volume 57, Issue 11, pp 2393–2404 | Cite as

Macrophage mTORC1 disruption reduces inflammation and insulin resistance in obese mice

  • Hongfeng Jiang
  • Marit Westerterp
  • Chunjiong Wang
  • Yi Zhu
  • Ding AiEmail author



Inflammatory factors secreted by macrophages play an important role in obesity-related insulin resistance. Being at the crossroads of a nutrient–hormonal signalling network, the mammalian target of rapamycin complex 1 (mTORC1) controls important functions in the regulation of energy balance and peripheral metabolism. However, the role of macrophage mTORC1 in insulin resistance is still unclear. In the current study, we investigated the physiological role of macrophage mTORC1 in regulating inflammation and insulin sensitivity.


We generated mice deficient in the regulatory associated protein of mTOR (Raptor) in macrophages, by crossing Raptor (also known as Rptor) floxed mice (Raptor flox/flox) with mice expressing Cre recombinase under the control of the Lysm-Cre promoter (Mac-Raptor KO). We fed mice chow or high-fat diet (HFD) and assessed insulin sensitivity in liver, muscle and adipose tissue. Subsequently, we measured inflammatory gene expression in liver and adipose tissue and investigated the role of Raptor deficiency in the regulation of inflammatory responses in peritoneal macrophages from HFD-fed mice or in palmitic acid-stimulated bone marrow-derived macrophages (BMDMs).


Mac-Raptor KO mice fed HFD had improved systemic insulin sensitivity compared with Raptor flox/flox mice. Macrophage Raptor deficiency reduced inflammatory gene expression in liver and adipose tissue, fatty liver and adipose tissue macrophage content in response to HFD. In peritoneal macrophages from mice fed with an HFD for 12 weeks, macrophage Raptor deficiency decreased inflammatory gene expression, through attenuation of the inactivation of Akt and subsequent inhibition of the inositol-requiring element 1α/clun NH2-terminal kinase–nuclear factor kappa-light-chain-enhancer of activated B cells (IRE1α/JNK/NFκB) pathways. Similarly, mTOR inhibition as a result of Raptor deficiency or rapamycin treatment decreased palmitic acid-induced inflammatory gene expression in BMDMs in vitro.


The disruption of mTORC1 signalling in macrophages protects mice against inflammation and insulin resistance potentially by inhibiting HFD- and palmitic acid-induced IRE1α/JNK/NFκB pathway activation.


Inflammation Insulin resistance mTORC1 



Activating transcription factor 6


Adipose tissue macrophage


Bone marrow-derived macrophage


Chow diet


Concanavalin A


Diet-induced obesity


Eukaryotic translation initiation factor 2α


Endoplasmic reticulum


High-fat diet


Intraperitoneal glucose tolerance test


Intraperitoneal insulin tolerance test


Inositol-requiring element 1α


cJun NH2-terminal kinase


Mammalian target of rapamycin complex 1/2


Nuclear factor κB


Nuclear magnetic resonance


RNA-dependent protein kinase-like ER kinase


p70 S6 kinase


Regulatory associated protein of mTOR


Saturated fatty acid




Toll-like receptor


Unfolded protein response


White adipose tissue


X box binding protein 1



The authors would like to thank A. Tall, Columbia University, New York, NY, USA, for his advice and help on experimental design and manuscript writing.


DA is supported by the National Natural Science Foundation of China (Nos 81322006 and 81370396). YZ is supported by the Major National Basic Research Grant of China (No. 2010CB912504). MW is supported by The Netherlands Organization of Scientific Research (NWO VENI – grant 916.11.072).

Duality of interest

The authors declare that there is no duality of interest associated with this manuscript.

Contribution statement

HJ contributed to the concept and design, data acquisition, analysis and interpretation and drafting of the article. MW contributed to the concept and design, data acquisition and revision of the article. CW and YZ contributed to the data acquisition and analysis and revision of the article. DA contributed to the concept and design, data acquisition, analysis and interpretation of data and revision of the article. DA is the guarantor of the work. All authors approved the final version.

Supplementary material

125_2014_3350_MOESM1_ESM.pdf (163 kb)
ESM Fig. 1 (PDF 163 kb)
125_2014_3350_MOESM2_ESM.pdf (367 kb)
ESM Fig. 2 (PDF 366 kb)
125_2014_3350_MOESM3_ESM.pdf (86 kb)
ESM Methods (PDF 86 kb)


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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Hongfeng Jiang
    • 1
  • Marit Westerterp
    • 1
    • 2
  • Chunjiong Wang
    • 3
  • Yi Zhu
    • 3
  • Ding Ai
    • 1
    • 3
    Email author
  1. 1.Division of Molecular Medicine, Department of MedicineColumbia UniversityNew YorkUSA
  2. 2.Department of Medical Biochemistry, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
  3. 3.Department of Physiology and PathophysiologyTianjin Medical UniversityTianjinPeople’s Republic of China

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