The pleiotropic effects of decanoic acid treatment on mitochondrial function in fibroblasts from patients with complex I deficient Leigh syndrome

Abstract

There is growing interest in the use of the ketogenic diet (KD) to treat inherited metabolic diseases including mitochondrial disorders. However, neither the mechanism whereby the diet may be working, nor if it could benefit all patients with mitochondrial disease, is known. This study focusses on decanoic acid (C10), a component of the medium chain triglyceride KD, and a ligand for the nuclear receptor PPAR-γ known to be involved in mitochondrial biogenesis. The effects of C10 were investigated in primary fibroblasts from a cohort of patients with Leigh syndrome (LS) caused by nuclear-encoded defects of respiratory chain complex I, using mitochondrial respiratory chain enzyme assays, gene expression microarray, qPCR and flow cytometry. Treatment with C10 increased citrate synthase activity, a marker of cellular mitochondrial content, in 50 % of fibroblasts obtained from individuals diagnosed with LS in a PPAR-γ-mediated manner. Gene expression analysis and qPCR studies suggested that treating cells with C10 supports fatty acid metabolism, through increasing ACADVL and CPT1 expression, whilst downregulating genes involved in glucose metabolism (PDK3, PDK4). PCK2, involved in blocking glucose metabolism, was upregulated, as was CAT, encoding catalase. Moreover, treatment with C10 also decreased oxidative stress in complex I deficient (rotenone treated) cells. However, since not all cells from subjects with LS appeared to respond to C10, prior cellular testing in vitro could be employed as a means for selecting individuals for subsequent clinical studies involving C10 preparations.Electronic supplementary materialThe online version of this article (doi:10.1007/s10545-016-9930-4) contains supplementary material, which is available to authorized users.

Neuronal decanoic acid oxidation is markedly lower than that of octanoic acid: A mechanistic insight into the medium‐chain triglyceride ketogenic diet

“…In studies conducted by Wlaź et al, C10 levels were also determined in the brains of mice following C10-enriched feeding. Interestingly, the concentration of C10 in mouse brain was found to average at 240-250μM, corresponding with therapeutic levels 4 reported in patient plasma on the MCT KD, as well as the optimum concentration (250µM) for mitochondrial proliferation in our previous studies 5,12 .…”

“…This can be further metabolised to generate ketones and/or enter the TCA cycle. Since medium-chain fatty acids are able to cross the blood brain barrier [25][26][27] and the enzymes of β-oxidation are reported to be present in neuronal cells 28,29 , we have in this study evaluated the ability of neuronal-like SH-SY5Y cells 12 to β-oxidise C8 and C10. We hypothesised that C10 would be relatively spared, which may result in a degree of accumulation of this fatty acid to occur.…”

Metabolic flexibility of mitochondrial respiratory chain disorders predicted by computer modelling

“…However, amino acids do not diffuse freely across the blood brain barrier (Smith, 2000). Complex I deficient patients have been placed on ketogenic diets with varying success (Roestenberg et al, 2012, Kanabus et al, 2016, Rahman, 2012). But although the ketone body acetoacetate was imported in simulations when complex I flux fell below 25% of its normal level, its contribution to ATP production was minimal (data not shown).…”

“…These therapies include anti-epileptics, correction of metabolic acidosis, supplementation of respiratory chain cofactors or precursors (such as flavin nucleotides) and antioxidants. Ketogenic diets, used for seizure control in (mitochondrial) epilepsy, have also been suggested to promote energy production in failing mitochondria of patients with complex I deficiencies (Roestenberg et al, 2012, Kanabus et al, 2016, Laugel et al, 2007, Leung et al, 1998, Paoli et al, 2014). However the molecular rationale and effectiveness of these treatments are not established (Chinnery et al, 2006).…”

Recognition, investigation and management of mitochondrial disease

“…Recently, decanoic acid, a C10 fatty acid produced in response to the ketogenic diet, has been found in vitro to stimulate mitochondrial biogenesis,44 and may have efficacy in primary mitochondrial disease although formal clinical trials are still needed 45…”