578 - Impaired stimulation-induced bioenergetic rewiring in immune cells from children with overweight/obesity

Publication Number: 4566.578

Shannon Rose, University of Tennessee Health Science Center College of Nursing, Memphis, TN, United States; Reid D. Landes, University of Arkansas for Medical Sciences, Little Rock, AR, United States; Emir Tas, UPMC Childrens Hospital of Pittsburgh, Mars, PA, United States; Elisabet Børsheim, UAMS, Arkansas Children's Nutrition Center, Little Rock, AR, United States

Background: Obesity-associated inflammation emerges early and drives insulin resistance (IR) and the development of type 2 diabetes in children. Therapeutically targeting immune cell metabolism may combat inflammation and prevent development of IR.

Objective: We aimed to understand how bioenergetics of peripheral blood mononuclear cells (PBMCs) change upon ex vivo stimulation with anti-CD3/anti-CD28. We hypothesized that these bioenergetic changes differ in children based on obesity status and insulin sensitivity.

Design/Methods: This cross-sectional study included 46 children aged 8-17 years. Exclusion criteria were having chronic illnesses (e.g. diabetes, neurologic, developmental, endocrine, hepatic, autoimmune, cardiac, and renal disorders), taking medications (antipsychotics, thyroid hormone replacement therapy, inhalation/oral steroids, insulin, anabolic drugs or stimulants) and having an infection in prior 2 weeks. Body mass index (BMI) and BMIz were determined via CDC growth charts. IR was estimated via the homeostatic model assessment of insulin resistance (HOMA-IR), calculated as (fasting glucose [mg/dL] × fasting insulin [µIU/mL])/405. Isolated PBMCs were cultured for 40 hours with or without stimulation with anti-CD3/anti-CD28 Dynabeads (1 bead/cell). ATP production rates from mitochondrial respiration (mitoATP) and glycolysis (glycoATP) were measured using the Seahorse XFe96 analyzer. Spearman correlations evaluated associations between PBMC bioenergetics, BMI z-scores, and HOMA-IR.

Results: Total ATP production (mitoATP + glycoATP) in resting PBMCs positively correlated with BMIz (r = 0.304, p = 0.040; Fig. 1A) and HOMA-IR (r = 0.312, p = 0.035; Fig. 1B). No significant correlations were observed when stimulation-induced changes in ATP production were examined among the entire cohort. However, when examining children with OW/OB separately (n = 21), change in glycoATP upon stimulation was negatively associated with both BMIz (r = -0.502; p = 0.020; Fig.1C) and HOMA-IR (r = -0.442; p = 0.045; Fig. 1D).

Conclusion(s): A higher rate of ATP production in resting PBMCs from children with higher BMIz and HOMA-IR suggests that immune cells may become more metabolically active with increasing obesity and IR. A more active metabolic state may impair stimulation-induced bioenergetic rewiring. Understanding the mechanisms driving metabolic activation in resting immune cells in children with OW/OB will provide clues to obesity-associated chronic inflammation and may offer critical insights into strategies for reducing inflammation and enhancing metabolic health in children with obesity.

Figure 1: Increasing BMIz and HOMA-IR are associated with increased ATP production in unstimulated PBMCs and with reduced upregulation of glycolysis upon CD3/CD28 stimulation.
In unstimulated PBMCs, Total ATP production rate (mitoATP + glycoATP) is positively correlated with BMIz (A) and HOMA-IR (B). Upon stimulation with CD3/CD28, the change in the rate of ATP produced by glycolysis (glycoATP) is negatively associated with BMIz (C) and HOMA-IR (D) in children with OW/OB. Normal weight (NW), Overweight/Obesity (OW/OB). Green circles represent values from normal weight children (n = 25). Orange circles represent values from overweight/obese children (n = 21).