Peroxisomes and peroxisomal functions in muscle: Studies with muscle cells from controls and a patient with the cerebro-hepato-renal (Zellweger) syndrome

Abstract

In the present study we investigated peroxisomal functions in cultured human muscle cells from control subjects and from a patient with the Zellweger syndrome, a genetic disease characterized by the absence of morphologically distinguishable peroxisomes in liver and kidney. In homogenates of cultured muscle cells from control subjects, catalase is contained within subcellular particles, acyl-CoA: dihydroxyacetonephosphate acyltransferase activity is present and palmitoyl-CoA can be oxidized by a peroxisomal β-oxidative pathway; these findings are indicative of the presence of peroxisomes in the cells. In homogenates of cultured muscle cells from the patient with the Zellweger syndrome, acyl-CoA: dihydroxyacetonephosphate acyltransferase activity was deficient, peroxisomal β-oxidation of palmitoyl-CoA was impaired and catalase was not particle-bound. These findings indicate that functional peroxisomes are absent in muscle from patients with the Zellweger syndrome. We conclude that cultured human muscle cells can be used as a model system to study peroxisomal functions in muscle and the consequences for this tissue of a generalized dysfunction of peroxisomes.