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Goossens C, Weckx R, Derde S, Vander Perre S, Derese I, Van Veldhoven PP, Ghesquière B, Van den Berghe G, Langouche L. Altered cholesterol homeostasis in critical illness-induced muscle weakness: effect of exogenous 3-hydroxybutyrate. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:252. [PMID: 34274000 PMCID: PMC8285799 DOI: 10.1186/s13054-021-03688-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 07/08/2021] [Indexed: 11/16/2022]
Abstract
Background Muscle weakness is a complication of critical illness which hampers recovery. In critically ill mice, supplementation with the ketone body 3-hydroxybutyrate has been shown to improve muscle force and to normalize illness-induced hypocholesterolemia. We hypothesized that altered cholesterol homeostasis is involved in development of critical illness-induced muscle weakness and that this pathway can be affected by 3-hydroxybutyrate. Methods In both human critically ill patients and septic mice, the association between circulating cholesterol concentrations and muscle weakness was assessed. In septic mice, the impact of 3-hydroxybutyrate supplementation on cholesterol homeostasis was evaluated with use of tracer technology and through analysis of markers of cholesterol metabolism and downstream pathways. Results Serum cholesterol concentrations were lower in weak than in non-weak critically ill patients, and in multivariable analysis adjusting for baseline risk factors, serum cholesterol was inversely correlated with weakness. In septic mice, plasma cholesterol correlated positively with muscle force. In septic mice, exogenous 3-hydroxybutyrate increased plasma cholesterol and altered cholesterol homeostasis, by normalization of plasma mevalonate and elevation of muscular, but not hepatic, expression of cholesterol synthesis genes. In septic mice, tracer technology revealed that 3-hydroxybutyrate was preferentially taken up by muscle and metabolized into cholesterol precursor mevalonate, rather than TCA metabolites. The 3-hydroxybutyrate protection against weakness was not related to ubiquinone or downstream myofiber mitochondrial function, whereas cholesterol content in myofibers was increased. Conclusions These findings point to a role for low cholesterol in critical illness-induced muscle weakness and to a protective mechanism-of-action for 3-hydroxybutyrate supplementation. Supplementary Information The online version contains supplementary material available at 10.1186/s13054-021-03688-1.
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Affiliation(s)
- Chloë Goossens
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 bus 503, 3000, Leuven, Belgium
| | - Ruben Weckx
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 bus 503, 3000, Leuven, Belgium
| | - Sarah Derde
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 bus 503, 3000, Leuven, Belgium
| | - Sarah Vander Perre
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 bus 503, 3000, Leuven, Belgium
| | - Inge Derese
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 bus 503, 3000, Leuven, Belgium
| | - Paul P Van Veldhoven
- Laboratory for Lipid Biochemistry and Protein Interactions, Department of Cellular and Molecular Medicine, KU Leuven, 3000, Leuven, Belgium
| | - Bart Ghesquière
- Metabolomics Expertise Center, Center for Cancer Biology, VIB, KU Leuven, 3000, Leuven, Belgium
| | - Greet Van den Berghe
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 bus 503, 3000, Leuven, Belgium
| | - Lies Langouche
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 bus 503, 3000, Leuven, Belgium.
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De Haas CG, Lopes-Cardozo M. Hydroxy- and non-hydroxy-galactolipids in developing rat CNS. Int J Dev Neurosci 1995; 13:447-54. [PMID: 7484215 DOI: 10.1016/0736-5748(95)00006-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Rat spinal cord (1-24 weeks postnatal) was analysed by HPLC for various species of galactolipids that accumulate in mammalian myelin during development. Cerebral tissue of the same animals was taken as reference. The levels of the major galactolipids, galactosylceramide (GalCer) and its sulfated analog (SGalCer), increased linearly during the first 2 months after birth. At 3 months, constant levels were reached that were approx. 4-fold (GalCer) and 2.5-fold (SGalCer) higher than in cerebral tissue of corresponding age. The accumulation of galactoglycerolipids slightly preceded that of galactosphingolipids. Levels of galacto-glycerolipids were much lower (4% of galactosphingolipids in 3-and 2.5% in 6-month-old spinal cord on weight basis) and decreased upon CNS maturation. During the first postnatal month, the ratio of non-hydroxy- over hydroxy-species (NFA/HFA) of cerebral GalCer declined from 2.2 to 0.5 whereas the NFA/HFA ratio for cerebral SGalCer increased from 1.0 to 1.8 in the same period. Through development the hydroxy-species contributed 56-60% to GalCer and 28-41% to SGalCer in spinal cord, whereas in cerebrum of 24-week-old rats 73% of GalCer and 48% of SGalCer was alpha-hydroxylated in the ceramide moiety. These data point to different developmental programs with respect to galactolipid metabolism of oligodendrocytes in high- (spinal cord) as compared to low-myelinated (cerebral) areas of rat CNS.
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Affiliation(s)
- C G De Haas
- Laboratory of Veterinary Biochemistry, Utrecht University, The Netherlands
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Lopes-Cardozo M, Larsson OM, Schousboe A. Acetoacetate and glucose as lipid precursors and energy substrates in primary cultures of astrocytes and neurons from mouse cerebral cortex. J Neurochem 1986; 46:773-8. [PMID: 3081684 DOI: 10.1111/j.1471-4159.1986.tb13039.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Primary cultures of astrocytes and neurons derived from neonatal and embryonic mouse cerebral cortex, respectively, were incubated with [3-14C]acetoacetate or [2-14C]glucose. The utilization of glucose and acetoacetate, the production of lactate, D-3-hydroxybutyrate, and 14CO2, and the incorporation of 14C and of 3H from 3H2O into lipids and lipid fractions were measured. Both cell types used acetoacetate as an energy substrate and as a lipid precursor; lactate was the major product of glucose metabolism. About 60% of the acetoacetate that was utilized by neurons was oxidized to CO2, whereas this was only approximately 20% in the case of cultured astrocytes. This indicates that the rate at which 14C-labeled Krebs cycle intermediates exchange with pools of unlabeled intermediates is much higher in astrocytes than in neurons. Acetoacetate is a better precursor for the synthesis of fatty acids and cholesterol than glucose, presumably because it can be used directly in the cytosol for these processes; preferential incorporation into cholesterol was not observed in these in vitro systems. We conclude that ketone bodies can be metabolized both by the glial cells and by the neuronal cells of developing mouse brain.
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