Loss of AMP-activated protein kinase in X-linked adrenoleukodystrophy patient-derived fibroblasts and lymphocytes.
X-Adrenoleukodystrophy (X-ALD) is a peroxisomal disorder characterized by accumulation of very-long-chain (VLC) fatty acids, which induces inflammatory disease and alterations in cellular redox, both of which are reported to play a role in the pathogenesis of the severe form of the disease (childhood cerebral ALD). While the mutation defect in ABCD1 gene is common to all forms of X-ALD it fails to account for the spectrum of phenotypic variability seen in X-ALD patients, strongly suggesting a role for as yet unidentified modifier gene(s). Here we report, for the first time, loss of AMP-activated protein kinase alpha1 (AMPKα1) in patient-derived fibroblasts and lymphocytes of the severe cerebral form of X-ALD (ALD), and not in the milder adrenomyeloneuropathy (AMN) form. Decrease in AMPK was observed at both protein and mRNA levels. AMPK loss in ALD patient-derived fibroblasts was associated with increased ubiquitination. Using the Seahorse Bioscience XF(e)96 Flux Analyzer for measuring the mitochondrial oxygen consumption and extracellular acidification rate we show that ALD patient-derived fibroblasts have a significantly lower "metabolic state" than AMN fibroblasts. Unstimulated ALD patient-derived lymphocytes had significantly higher proinflammatory gene expression. Selective AMPK loss represents a novel physiopathogenic factor in X-ALD disease mechanism. Strategies aimed at upregulating/recovering AMPK levels might have beneficial therapeutic effects in X-ALD.
Department of Neurology, Henry Ford Health System, Detroit, MI 48202, United States. Electronic address: jsingh2@hfhs.org.
Jaspreet
J
Singh
Department of Neurology, Henry Ford Health System, Detroit, MI 48202, United States.
Shailendra
S
Giri
D055372:AMP-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism; D000326:Adrenoleukodystrophy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics; D015536:Down-Regulation; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D015151:Immunoblotting; D008214:Lymphocytes / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D010101:Oxygen Consumption; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025801:Ubiquitin / Q000378:metabolism
D016207:Cytokines; D025801:Ubiquitin; D052247:Nitric Oxide Synthase Type II; D055372:AMP-Activated Protein Kinases; C526180:PRKAA1 protein, human
AMPKα1; ECAR; Inflammation; OCR; Ubiquitin; X-ALD