{
"METABOLOMICS WORKBENCH":{"STUDY_ID":"ST003004","ANALYSIS_ID":"AN004935","VERSION":"1","CREATED_ON":"12-14-2023"},

"PROJECT":{"PROJECT_TITLE":"Uncoupling Metabolic Health from Thermogenesis via BCAA Flux in Brown Fat","PROJECT_TYPE":"MS quantitative analysis","PROJECT_SUMMARY":"Brown adipose tissue (BAT) is best known for thermogenesis. Whereas numerous studies in rodents found tight associations between the metabolic benefits of BAT and enhanced whole-body energy expenditure, emerging evidence in humans suggests that BAT is protective against Type 2 diabetes independent of body-weight. The underlying mechanism for this dissociation remained unclear. Here, we report that impaired mitochondrial flux of branched-chain amino acids (BCAA) in BAT, by deleting mitochondrial BCAA carrier (MBC, encoded by Slc25a44), was sufficient to cause systemic insulin resistance without affecting whole-body energy expenditure or body-weight. We found that brown adipocytes catabolized BCAAs in the mitochondria as essential nitrogen donors for the biosynthesis of glutamate, N-acetylated amino acids, and one of the products, glutathione. BAT-selective impairment in mitochondrial BCAA flux led to elevated oxidative stress and insulin resistance in the liver, accompanied by reduced levels of BCAA-derived metabolites in the circulation. In turn, supplementation of glutathione restored insulin sensitivity of BAT-specific MBC knockout mice. Notably, a high-fat diet rapidly impaired BCAA catabolism and the synthesis of BCAA-nitrogen derived metabolites in the BAT, while cold-induced BAT activity is coupled with an active synthesis of these metabolites. Together, the present work uncovers a mechanism through which brown fat controls metabolic health independent of thermogenesis via BCAA-derived nitrogen carriers acting on the liver.","INSTITUTE":"BIDMC","LAST_NAME":"Wang","FIRST_NAME":"Dandan","ADDRESS":"3 Blackfan Circle, Boston, MA, 02115, USA","EMAIL":"dandanwang2022@gmail.com","PHONE":"5083733714","DOI":"http://dx.doi.org/10.21228/M8MF0Z"},

"STUDY":{"STUDY_TITLE":"Extracellular fluid metabolomics of BAT and eWAT","STUDY_SUMMARY":"We quantified metabolites of extracellular fluid samples from BAT and eWAT. Briefly, we collected the BAT_EF samples and eWAT_EF samples from 12 weeks chow diet C57BL/6J mice (n=5). We run the EF metabolomics using high ph HILIC method on Exploris 240.","INSTITUTE":"Harvard Medical School","LAST_NAME":"Wang","FIRST_NAME":"Dandan","ADDRESS":"3 Blackfan Circle, Boston, MA, 02115, USA","EMAIL":"dandanwang2022@gmail.com","PHONE":"5083733714","SUBMIT_DATE":"2023-12-12"},

"SUBJECT":{"SUBJECT_TYPE":"Mammal","SUBJECT_SPECIES":"Mus musculus","TAXONOMY_ID":"10090","GENOTYPE_STRAIN":"C57BL/6J","AGE_OR_AGE_RANGE":"12 weeks","WEIGHT_OR_WEIGHT_RANGE":"25-30g","GENDER":"Male"},
"SUBJECT_SAMPLE_FACTORS":[
{
"Subject ID":"-",
"Sample ID":"EF_BAT_neg_1",
"Factors":{"Tissue":"BAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_BAT_neg_1.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_BAT_neg_2",
"Factors":{"Tissue":"BAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_BAT_neg_2.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_BAT_neg_3",
"Factors":{"Tissue":"BAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_BAT_neg_3.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_BAT_neg_4",
"Factors":{"Tissue":"BAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_BAT_neg_4.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_BAT_neg_5",
"Factors":{"Tissue":"BAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_BAT_neg_5.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_eWAT_neg_1",
"Factors":{"Tissue":"eWAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_eWAT_neg_1.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_eWAT_neg_2",
"Factors":{"Tissue":"eWAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_eWAT_neg_2.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_eWAT_neg_3",
"Factors":{"Tissue":"eWAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_eWAT_neg_3.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_eWAT_neg_4",
"Factors":{"Tissue":"eWAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_eWAT_neg_4.RAW"}
},
{
"Subject ID":"-",
"Sample ID":"EF_eWAT_neg_5",
"Factors":{"Tissue":"eWAT"},
"Additional sample data":{"Sample type":"EF","RAW_FILE_NAME":"EF_eWAT_neg_5.RAW"}
}
],
"COLLECTION":{"COLLECTION_SUMMARY":"Animals were sacrificed immediately by cervical dislocation and tissues were rapidly extracted. Tissues were subjected to centrifugation (10 min, 800 g, 4°C) following placement in a 20 μm nylon mesh filter (EMD Millipore).","SAMPLE_TYPE":"Extracellular fluid"},

"TREATMENT":{"TREATMENT_SUMMARY":"All mice were housed under a 12 h – 12 h light/dark cycle. Room-temperature mice were housed at 23˚C in ventilated cages with an ACH of 25. Mice were fed a standard diet (Lab Diet 5008) and had free access to food and water."},

"SAMPLEPREP":{"SAMPLEPREP_SUMMARY":"Animals were sacrificed immediately by cervical dislocation. Tissues were subjected to centrifugation (10 min, 800 g, 4°C) following placement in a 20 μm nylon mesh filter (EMD Millipore). Metabolites were extracted by adding extraction buffer at a ratio of 1:100 interstitial fluid to methanol. Samples were then centrifuged twice (5 min, 10,000 g, 4°C) and supernatant was collected."},

"CHROMATOGRAPHY":{"INSTRUMENT_NAME":"Thermo Vanquish","COLUMN_NAME":"Waters ACQUITY UPLC BEH Amide (100 x 2.1mm,1.7um)","COLUMN_TEMPERATURE":"25 °C","FLOW_GRADIENT":"The linear gradient eluted from 95% B (0.0–1 min), 95% B to 65% B (1–7.0 min), 65% B to 40% B (7.0–8.0 min), 40% B (8.0–9.0 min), 40% B to 95% B (9.0–9.1 min), then stayed at 95% B for 5.9 min.","FLOW_RATE":"0.4 mL/min","SOLVENT_A":"100% water; 25mM ammonium acetate; 25mM ammonium hydroxide","SOLVENT_B":"100% acetonitrile","CHROMATOGRAPHY_TYPE":"HILIC"},

"ANALYSIS":{"ANALYSIS_TYPE":"MS"},

"MS":{"INSTRUMENT_NAME":"Thermo orbitrap exploris 240","INSTRUMENT_TYPE":"Orbitrap","MS_TYPE":"ESI","MS_COMMENTS":"ESI source parameters were set as follows: spray voltage, 3500 V or −2800 V, in positive or negative modes, respectively; vaporizer temperature, 350 °C; sheath gas, 50 arb; aux gas, 10 arb; ion transfer tube temperature, 325 °C. The full scan was set as: orbitrap resolution, 60,000; maximum injection time, 100 ms; scan range, 70–1050 Da. The ddMS2 scan was set as: orbitrap resolution, 30,000; maximum injection time, 60 ms; top N setting, 6; isolation width, 1.0 m/z; HCD collision energy (%), 30; Dynamic exclusion mode was set as auto. The data was analyzed by Compound Discoverer 3.3.","ION_MODE":"NEGATIVE","MS_RESULTS_FILE":"ST003004_AN004935_Results.txt UNITS:Peak area Has m/z:Yes Has RT:Yes RT units:Minutes"}

}