Date: 18, May, 2023

Dataset Title: Clofazimine-Mediated, Age-Related Changes in Skeletal Muscle Mitochondrial Metabolites

Dataset Creators: Jennifer Diaz-Espinosa, Kathleen A. Stringer and Gus R. Rosania

Funding: The National Institutes of Health (NIH) under award numbers R01GM127787 (GRR), R35GM136312 (KAS), P30AR069620 (K Jepsen), and T32GM140223 (L Isom). 

Research Overview:
These data were produced from a study that assessed mitochondrial metabolic function by measuring two metabolites, l-carnitine and acetylcarnitine, to determine their effectiveness as candidate clinical biomarkers for age-related, drug-induced alterations in mitochondrial metabolism. To study age and medication-related changes in mitochondrial metabolism, we administered the FDA-approved mitochondriotropic drug, clofazimine (CFZ), or vehicle for to young and old mice. 
These findings are described in our Metabolites 2023 manuscript: Clofazimine-Mediated, Age-Related Changes in Skeletal Muscle Mitochondrial Metabolites. 

Methodology: 
To study age and medication-related changes in mitochondrial metabolism, an FDA-approved mitochondriotropic drug, clofazimine (CFZ), or vehicle was administered for 8-weeks to young (4-weeks-old) and old (61-weeks-old) male C57BL/6J mice. At the end of treatment, food consumption was monitored via specialized cages for 18 hours, after which animals were euthanized by CO2 inhalation following a cardiac puncture for blood sample acquisition. Immediately after euthanasia, the Cardiac (heart) and skeletal (gastrocnemius, GAS) muscles were isolated, washed with 1X phosphate- buffered saline (PBS), blotted dry, weighed (mg), and flash-frozen in liquid nitrogen. Whole blood and cardiac and skeletal muscle were analyzed for l-carnitine, acetylcarnitine, and CFZ levels. Concentrations (μg/mL) were derived from an internal standard as measured by liquid chromatography (LC)-mass spectroscopy (MS)/MS. To convert CFZ muscle data from μg/mL to μg, concentration values were multiplied by the mass (g) of each sample. Blood concentration data were converted from μg/mL to μM by dividing concentration (μg/mL) by molecular weight (l-carnitine, 161.2; acetylcarnitine, 203.2; clofazimine, 473.4) and multiplying by 1000. Muscle function (endurance) was measured via a treadmill test. The quantification of macrophage population was conducted by analyzing F480-stained tissue sections, which were digitized and processed using the positive cell detection algorithm within the open-source program QuPath (version 0.4.3; University of Edinburgh, Edinburgh, Scotland, UK). The number of F480-stained cells was reported as the count of positive cells per square millimeter of tissue area.

File Inventory: 

Excel file name: Cardiac and Skeletal Muscle to Body Ratio: Represents all data acquired at the end of CFZ treatment using the terminal tissue and body mass 
Excel file name: Carnitine Levels in Whole Blood and Cardiac and Skeletal mMscle: Represents all data acquired from mice at the end of CFZ and vehicle treatment 
Excel file name: CFZ Dose and Levels in Whole Blood and Cardiac and Skeletal Muscle: Represents all data acquired from CFZ-treated mice at the end of treatment
Excel file name: CFZ Induced Body Mass Change and Food Consumption: Represents all data acquired from mice at the end of CFZ and vehicle treatment
Excel file name: Endurance: Represents all data acquired from mice one week before the end of CFZ and vehicle treatment
Excel file name: Skeletal Muscle Macrophage Population: Represents all data acquired from mice at the end of CFZ and vehicle treatment