Constitutive UCP1 expression is associated with a glucose-dependent phenotype in murine mesenchymal stem cells.

Mesenchymal stem cells (MSCs) possess significant metabolic plasticity, enabling them to adapt dynamically to environmental stressors during tissue repair. Although UCP1 is associated with nonshivering thermogenesis in brown adipose tissue (BAT) through the uncoupling of oxidative phosphorylation, its impact on MSCs metabolism remains unexplored. Herein, we evaluated the ectopic expression of UCP1 in MSCs and its effects on classical surface markers, the redox state and glucose metabolism. MSCs were genetically modified to constitutively overexpress UCP1 using a lentiviral construct. Transduction efficiency was evaluated by direct UCP1 expression and the co-expressed EGFP fluorescent tag. Surface marker phenotype and proliferation were evaluated by expression of multipotency markers and metabolic activity, respectively. Metabolic phenotypes were assessed by measuring mitochondrial membrane potential (ΔΨm), quantifying cytoplasmic and mitochondrial reactive oxygen species (ROS), and evaluating glucose uptake via the 2-NBDG assay, while key glycolytic markers were evaluated by qPCR and immunoblot. UCP1-overexpressing MSCs showed a marked reduction in ΔΨm; however, normalized intracellular ATP levels remained stable across varying cell densities. Crucially, persistent UCP1 expression did not affect surface markers or cell metabolic activity, retaining their classical surface marker profile; furthermore, the engineered cells showed reduced baseline ROS levels compared with the parental line. Most notably, MSC-UCP1 cells showed increased glucose uptake and increased sensitivity to glucose deprivation, displaying increased expression of glycolytic markers. Our data indicate that constitutive UCP1 expression is associated with a shift in MSC metabolism towards a glucose-dependent state. This distinct metabolic profile highlights the plasticity of MSCs energetics and suggests a potential therapeutic application for genetically engineered MSCs in treating energy imbalance disorders such as obesity and type 2 diabetes.