We determined that brown adipose tissue-specific uncoupling protein-1 (UCP-1) mRNA is expressed in the lipoma of a multiple symmetric lipomatosis patient bearing the 8344 mutation in the tRNALys gene of mitochondrial DNA.
Cultured MSL adipocytes were able to synthesize UCP-1 (the selective marker of brown adipocytes), but unlike that of normally functioning brown fat cells, the expression of the UCP-1 gene was not significantly induced by NA.
Downregulation of CAPSL and upregulation of UCP1 were common features in MSL fat while the known MSL genes MFN2 and LIPE did not show consistent alterations.