Effects of an Acute High Fat Load on Peripheral Blood Mononuclear Cell Response among Women
Authors: Pearson Regis C , Winchester Lee , Olenick Alyssa , Johnson Julia , Shaker Nuha , Blankenship Maire , Oregon Evelyn , Hoover Don , Maples Jill M 
Published: November 2023

The immune system and other cellular defense systems (i.e. metabolism) are interlinked and can respond to environmental stimuli. Inflammation, due to the over expression of pro‐inflammatory cytokines being released from peripheral blood mononuclear cells (PBMCs), is associated with a wide variety of disease states including cardiovascular and metabolic disease. Previous studies have indicated that PBMCs can respond to dietary stimuli, such as a high fat diet, which modulates the up‐regulation of pro‐inflammatory cell signaling. African American (AA) women compared to Caucasian (CA), have elevated pro‐inflammatory profiles which have been associated with an increased prevalence of metabolic disease. However, no study has investigated the influence ethnicity on PBMC gene expression in response to an acute dietary stimulus. Therefore, the purpose of this study is to investigate the impact that a typical, Western, high‐fat meal has on the expression of inflammatory genes from PBMCs isolated from AA and CA women.

METHODS

16 women, 6 AA (age: 26.33±7.23) and 10 CA (age: 26.93±6.27), were recruited to consume a high fat shake. PBMCs were isolated at baseline (pre‐shake) and 4‐hours post shake ingestion (post‐shake) and cultured for 3 hours in 1) RPMI‐1640 media (control) or 2) RPMI‐1640 media supplemented with 250uM 1:1 Oleate:Palmitate (lipid‐treated); resulting in the following experimental conditions: 1) pre‐shake, control; 2) pre‐shake, lipid‐treated; 3) post‐shake, control; and 4) post‐shake, lipid‐treated. Using RT‐PCR, we evaluated gene expression of TNF‐a, IL‐6, IL‐8, and IL‐10. A repeated‐measures ANOVA with emphasis on a time (pre‐ vs. post‐shake) × treatment (control vs. lipid‐treated) × ethnicity (AA vs. CA) interaction were performed.

RESULTS

There was a significant time effect for IL‐8 gene expression (p=0.04), where IL‐8 expression significantly increased post‐shake in both the control (pre‐5.28±0.36 vs post‐5.46±0.27; p=0.05) and lipid‐treated (pre‐5.33±0.31 vs. post‐5.60±0.35; p=0.01) conditions for all participants. In the post‐shake, control condition IL‐8 gene expression was significantly higher among the AA women (AA 5.84±0.38 vs. CA 5.48±0.30; p=0.03). For IL‐6 gene expression, the interaction between time × treatment × ethnicity approached significance (p=0.07) and a significant time × treatment interaction (p=0.04) was observed. There was an overall trend for a decrease in the expression of IL‐6 post‐shake (compared to pre‐shake) in the lipid treated condition (pre‐3.11±0.61 vs. post‐2.77±0.59; p=0.06). Among the AA women there was a significant decrease in IL‐6 gene expression post‐shake (compared to pre‐shake) in the lipid‐treated condition (pre‐3.22±0.64 vs. post‐2.54±0.59; p=0.04). There were no baseline differences between ethnic groups in TNF‐a, IL‐6, IL‐8, and IL‐10 expression (pre‐shake, control).

CONCLUSION

This study showed that the ingestion of a high fat shake does effect PBMC gene expression response in healthy women; with specific gene expression differences seen in AA women.

Support or Funding Information

NIH NIGMS Grant 5P20GM103436, Western Kentucky University Graduate School, WKU College of Health and Human Services