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Updated: May 16, 2026
Assessing Whole-Body Lipid-Handling Capacity in Mice
Published on: November 24, 2020
Mice fed with a high fat diet show a decrease in the expression of "toll like receptor (TLR)2 and TLR6 mRNAs in
G Betanzos-Cabrera1, D Estrada-Luna, H Belefant-Miller
1Área Académica de Nutrición, Instituto de Ciencias de Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca, Mexico.
Introduction:
Pattern-recognition receptors (PRRs), which include Toll-like Receptor (TLRs) and Nacht leucine-rich repeat proteins (NLRP/NALPs), are molecules of innate immunity able to recognize a wide variety of ligands present in microorganisms and human tissues. Adipocytes (fat cells) may play an important role in the physiological regulation of their own immune responses via TLRs. During obesity, the inflammatory pathway is triggered and insulin responsiveness is altered in fat tissue as a result of TLR4 activation by dietary lipids.
Objective:
Here, we investigate if other PRR family members could also participate in the inflammatory processes in the adipose tissue of obese mice.
Methods:
The mRNA expression of TLRs, the NLRP3-inflammasome (NLRP3, ASC, caspase-1 and IL-lbeta), IL-6, and TNFα in the hepatic and adipose tissues of mice fed with a high fat diet (HFD) were studied by RT-PCR.
Results:
Adipose tissue from mice fed with a HFD had decreased expression levels of TLR2, TLR6 and TLR7 and was similar to the pattern in hepatic tissue HFD mice. IL-6 and TNF-α expression also were decreased in adipose tissue of mice fed with a HFD. NLRP3-inflammasome expression was not modified.
Conclusion:
These results suggest that the low expression of TLR2, and TLR6 in the mice fed with a HFD could be regulating the inflammation induced by the diet employed in this study.
Insights
Obesity-induced inflammation in fat tissue involves pattern-recognition receptors (PRRs). High-fat diets decreased Toll-like Receptor (TLR) 2, 6, and 7 expression, suggesting a regulatory role in diet-induced inflammation.
Area of Science:
- Immunology
- Metabolic Diseases
- Cell Biology
Background:
- Pattern-recognition receptors (PRRs), including Toll-like Receptors (TLRs), are key innate immunity molecules recognizing microbial and tissue ligands.
- Adipocytes (fat cells) utilize TLRs for immune response regulation, with TLR4 activation by lipids triggering inflammation and altering insulin sensitivity during obesity.
Purpose of the Study:
- Investigate the role of additional PRR family members in adipose tissue inflammation in obese mice.
- Determine how high-fat diet (HFD) affects PRR expression in adipose and hepatic tissues.
Main Methods:
- Quantitative reverse transcription PCR (RT-PCR) was used to analyze mRNA expression.
- Examined TLRs, NLRP3-inflammasome components (NLRP3, ASC, caspase-1, IL-1β), IL-6, and TNFα.
- Studied hepatic and adipose tissues from mice fed a HFD.
Main Results:
- High-fat diet (HFD) consumption led to decreased expression of TLR2, TLR6, and TLR7 in adipose tissue, mirroring hepatic tissue patterns.
- Interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNFα) expression were also reduced in adipose tissue of HFD mice.
- NLRP3-inflammasome expression remained unchanged in adipose tissue from HFD mice.
Conclusions:
- Reduced expression of TLR2 and TLR6 in adipose tissue of HFD mice may play a regulatory role in diet-induced inflammation.
- These findings highlight specific TLRs' involvement in the inflammatory response to high-fat diets in adipose tissue.
