Long-chain fatty acid oxidation disorders (LC-FAODs) cause energy deficits in heart and skeletal muscle that are only partially corrected by current medium-chain lipid therapies such as triheptanoin. We find that heart and muscle lack medium-chain acyl-CoA synthetases, limiting the capacity for β-oxidation of medium-chain fatty acids. Instead, heart and muscle mitochondria robustly respire on medium-chain acylcarnitines. The mitochondrial matrix enzyme carnitine acetyltransferase (CrAT) efficiently converts orally delivered octanoylcarnitine (C8-carnitine) to octanoyl-CoA for energy generation. C8-carnitine exhibits twice the oral bioavailability of triheptanoin and distributes to muscle and heart. A single oral dose significantly enhances grip strength and treadmill endurance while attenuating lactic acidosis in 2 mouse models of LC-FAODs. Thus, medium-chain acylcarnitines overcome a previously unrecognized metabolic bottleneck in LC-FAOD muscle and may represent an alternative to triglyceride-based therapies for bioenergetic disorders.
Keaton J. Solo, Yuxun Zhang, Sivakama S. Bharathi, Bob B. Zhang, Adam C. Richert, Alexandra V. Schmidt, Clinton Van’t Land, Olivia D’Annibale, Timothy C. Wood, Eric S. Goetzman
Usage data is cumulative from October 2025 through December 2025.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 596 | 2 |
| 262 | 0 | |
| Figure | 50 | 0 |
| Supplemental data | 147 | 0 |
| Citation downloads | 104 | 0 |
| Totals | 1,159 | 2 |
| Total Views | 1,161 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.