Overview

• A peer-reviewed Nature paper from Washington University reports that peroxisomal ACOX2 enables heat production independent of mitochondrial UCP1.
• Mice lacking ACOX2 in brown fat produced less heat, showed poorer cold tolerance, developed insulin resistance, and gained more weight on a high-fat diet.
• Overexpressing ACOX2 in brown fat boosted heat output, improved cold tolerance and insulin sensitivity, and limited weight gain under the same diet.
• A fluorescent heat sensor and infrared thermal imaging showed that ACOX2 activity raises brown-fat cell temperature and that ACOX2-deficient tissue emits less heat.
• The pathway depends on branched fatty acids present in dairy, breast milk, and some gut microbes, and investigators are exploring dietary or drug approaches with a provisional patent filed, with human relevance yet to be demonstrated.