P760 - INTAKE OF SATURATED FATTY ACIDS INDUCED INFILTRATION OF M1 MACROPHAGES INTO THE ADIPOSE TISSUE OF LDLR-KO MICE

P760

INTAKE OF SATURATED FATTY ACIDS INDUCED INFILTRATION OF M1 MACROPHAGES INTO THE ADIPOSE TISSUE OF LDLR-KO MICE

M. S. F. Lavrador^1,2, D. E. Cintra^3,4, A. M. Lottenberg^3,5,6,*, R. M. Machado^1,2

¹Hospital Israelita Albert Einstein, Sao Paulo, ²Nutrigenomics and Lipids Research Center – CELN – University of Campinas – UNICAMP, São Paulo, ³Nutrigenomics and Lipids Research Center – CELN – University of Campinas – UNICAMP, Sao Paulo, ⁴Nutritional Genomics Laboratory – University of Campinas – UNICAMP, Campinas, ⁵Laboratorio de Lipides (LIM-10), Hospital das Clínicas (HCFMUSP) da Faculdade de Medicina da Universidade de São Paulo), ⁶São Paulo, Hospital Israelita Albert Einstein, Sao Paulo, Brazil

 

Rationale:  Fatty acids modulate inflammatory responses in a tissue-specific manner, with saturated and trans fatty acids being particularly known for their pro-inflammatory properties. This study aimed to evaluate the effects of different dietary fatty acids on the inflammatory profile of adipose tissue.

Methods:  Weaning male LDLr-KO mice were randomly assigned to three groups and fed high-fat diets providing 40% of energy as fat, enriched either with trans (TRANS), polyunsaturated (PUFA), or saturated (SFA) fatty acids for 16 weeks. Dietary intake, body weight, and subcutaneous and epididymal fat pad weights were assessed. Biomolecular mapping was performed to identify M1 macrophages (CD11b⁺) in subcutaneous adipose tissue (ScAT).

Results:  Food intake was similar across all groups; weight gain in the SFA group did not differ significantly from that observed in PUFA- and TRANS-fed mice; ScAT mass was comparable between the SFA and PUFA groups, while TRANS-fed mice exhibited reduced ScAT compared to both (1). Mice fed the SFA diet showed a widespread distribution of pro-inflammatory M1 (CD11b⁺) macrophages in ScAT (31.11 ± 12.80) cells. This was significantly higher than in PUFA-fed mice (10 ± 4.23; p < 0.05), but not significantly different from TRANS-fed mice (21.2 ± 3.03).

 

 

 

 

 

 

 

 

Conclusion:  Saturated fatty acids have been shown to activate Toll-like receptor 4 (TLR4) on resident macrophages, promoting the chemotaxis of inflammatory cells and contributing to both local and systemic inflammation. In line with this, our findings revealed that SFA intake led to increased infiltration of pro-inflammatory M1 macrophages in the ScAT of LDLr-KO mice compared to those fed PUFA, supporting the pro-inflammatory role of saturated fat consumption in adipose tissue.

References: 1. Machado RM et al. J Nutr. 2010 Jun;140(6):1127-32.

Disclosure of Interest: None declared