Increased expression of triggering receptor expressed on myeloid cells-1 in the population with obesity and insulin resistance

Authors


  • Funding agencies: This study was supported by a research grant to KCN from the LB692 Nebraska Tobacco Settlement Funds to Creighton University and by the research grants R01HL116042 and R01HL128063 from the National Institutes of Health to DKA.

  • Disclosure: The authors declare no conflict of interest.

  • Author contributions: SS: designing experiment, conducting experiments, acquiring and analyzing data, writing the manuscript; PKP: providing tissue samples; VR: conducting experiments, editing the manuscript; PS: analyzing the histological slides; DKA: concept of the study, designing experiments, providing reagents, analysis and critical evaluation of the data, editing the manuscript; KCN: concept of the study, designing experiments, providing samples and reagents, writing and editing the manuscript.

Abstract

Objective

Triggering receptor expressed on myeloid cells (TREM)−1 has recently been recognized as one of the potent amplifiers of acute and chronic inflammation. However, the exact role of TREM-1 in regard to insulin insensitivity is unknown.

Methods

mRNA transcripts and protein expression of TREM-1, TREM-2, and TREM-1/TREM-2 ratio were examined in the tissue biopsies (liver, omentum, and subcutaneous fat) and blood samples (neutrophils and monocytes) of subjects with obesity and diabetes (SO+ D+; n = 15), subjects with obesity but not diabetes (SO+ D; n = 7), and subjects without obesity (BMI < 30) and diabetes (SOD; n = 5).

Results

The immunofluorescence and RT-PCR revealed significant increase in TREM-1, decrease in TREM-2, and increase in the TREM1/TREM2 ratio in SO+ D+ group compared with other groups. Overall, increased liver TREM-1 expression and soluble-TREM-1 were found in SO+ D+ group compared with SO+ D group (100% vs. 57.14%, r = 0.582; P = 0.023). TREM-1 was significantly increased in all subjects with obesity and those with HOMA-IR index of >2.

Conclusions

TREM-1 was found to be significantly higher in tissues biopsies and blood of subjects with obesity. Greater expression and activity of TREM-1 suggest a possible role in the underlying pathophysiology of obesity and associated comorbidities.

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