Freeman, Mason

Phone: 617-724-7704


Dr. Freeman graduated from Harvard College and received his M.D. at the University of California, San Francisco in 1979. He served as an intern, resident, and endocrinology fellow in the Department of Medicine at the Massachusetts General Hospital and was Chief Resident in Medicine at the MGH in 1985. Following clinical training, he worked as a post-doctoral research fellow in the Biology Department of the Massachusetts Institute of Technology before returning to the MGH to head the Cardiovascular Health Center. He became Chief of the Lipid Metabolism Unit at the MGH in 1992.

Mason’s research work has centered on the role of macrophages in atherosclerosis with particular interest in the trafficking of lipids through these cells. While at MIT, he and his colleagues cloned the first macrophage scavenger receptor. Over the years, his lab has studied the mechanisms of atherosclerotic foam cell formation and the impact of lipids on activation of vascular inflammatory responses. The lab has also made fundamental contributions to our understanding of reverse cholesterol transport via its work on the topology and biochemistry of the ABCA1 transporter, mutations in which cause Tangier disease. In the last two years, the lab has expanded its interest to the other ABCA transporters, all of which appear to play a role in cellular lipid trafficking.

Mason remains clinically active, teaching medical students, residents, and endocrine fellows rotating through the MGH clinical services and he continues to direct the MGH Lipid Clinic that he founded in 1986.

Selected Publications (from total of 117)


Zimmer S, Grebe A, Bakke SS, Bode N, Halvorsen B, Ulas T, Skjelland M, De Nardo D, Labzin LI, Kerksiek A, Hempel C, Heneka MT, Hawxhurst V, Fitzgerald ML, Trebicka J, Björkhem I, Gustafsson JÅ, Westerterp M, Tall AR, Wright SD, Espevik T, Schultze JL, Nickenig G, Lütjohann D, Latz E
Cyclodextrin promotes atherosclerosis regression via macrophage reprogramming.
Sci Transl Med. 2016;8(333):333ra50 - PMID: 27053774 - PMCID: PMC4878149
Sakae N, Liu CC, Shinohara M, Frisch-Daiello J, Ma L, Yamazaki Y, Tachibana M, Younkin L, Kurti A, Carrasquillo MM, Zou F, Sevlever D, Bisceglio G, Gan M, Fol R, Knight P, Wang M, Han X, Fryer JD, Fitzgerald ML, Ohyagi Y, Younkin SG, Bu G, Kanekiyo T
ABCA7 Deficiency Accelerates Amyloid-? Generation and Alzheimer's Neuronal Pathology.
J Neurosci. 2016;36(13):3848-59 - PMID: 27030769 - PMCID: PMC4812140
Bushinsky DA, Williams GH, Pitt B, Weir MR, Freeman MW, Garza D, Stasiv Y, Li E, Berman L, Bakris GL
Patiromer induces rapid and sustained potassium lowering in patients with chronic kidney disease and hyperkalemia.
Kidney Int. 2015;88(6):1427-1433 - PMID: 26376130 - PMCID: PMC4678168
Siegel MO, Borkowska AG, Dubrovsky L, Roth M, Welti R, Roberts AD, Parenti DM, Simon GL, Sviridov D, Simmens S, Bukrinsky M, Fitzgerald ML
HIV infection induces structural and functional changes in high density lipoproteins.
Atherosclerosis. 2015;243(1):19-29 - PMID: 26343868 - PMCID: PMC4609619
Bakris GL, Pitt B, Weir MR, Freeman MW, Mayo MR, Garza D, Stasiv Y, Zawadzki R, Berman L, Bushinsky DA,
Effect of Patiromer on Serum Potassium Level in Patients With Hyperkalemia and Diabetic Kidney Disease: The AMETHYST-DN Randomized Clinical Trial.
JAMA. 2015;314(2):151-161 - PMID: 26172895
Ramezani A, Dubrovsky L, Pushkarsky T, Sviridov D, Karandish S, Raj DS, Fitzgerald ML, Bukrinsky M
Stimulation of Liver X Receptor Has Potent Anti-HIV Effects in a Humanized Mouse Model.
J Pharmacol Exp Ther. 2015;354(3):376-83 - PMID: 26126533 - PMCID: PMC4538872
Fox CS, Hall JL, Arnett DK, Ashley EA, Delles C, Engler MB, Freeman MW, Johnson JA, Lanfear DE, Liggett SB, Lusis AJ, Loscalzo J, MacRae CA, Musunuru K, Newby LK, O'Donnell CJ, Rich SS, Terzic A
Future Translational Applications From the Contemporary Genomics Era: A Scientific Statement From the American Heart Association.
Circulation. 2015;131(19):1715-36 - PMID: 25882488 - PMCID: PMC4825323
Midtbø LK, Borkowska AG, Bernhard A, Rønnevik AK, Lock EJ, Fitzgerald ML, Torstensen BE, Liaset B, Brattelid T, Pedersen TL, Newman JW, Kristiansen K, Madsen L
Intake of farmed Atlantic salmon fed soybean oil increases hepatic levels of arachidonic acid-derived oxylipins and ceramides in mice.
J Nutr Biochem. 2015;26(6):585-95 - PMID: 25776459
Stitziel NO, Peloso GM, Abifadel M, Cefalù AB, Fouchier S, Motazacker MM, Tada H, Larach DB, Awan Z, Haller JF, Pullinger CR, Varret M, Rabès JP, Noto D, Tarugi P, Kawashiri MA, Nohara A, Yamagishi M, Risman M, Deo R, Ruel I, Shendure J, Nickerson DA, Wilson JG, Rich SS, Gupta N, Farlow DN, , Neale BM, Daly MJ, Kane JP, Freeman MW, Genest J, Rader DJ, Mabuchi H, Kastelein JJ, Hovingh GK, Averna MR, Gabriel S, Boileau C, Kathiresan S
Exome Sequencing in Suspected Monogenic Dyslipidemias.
Circ Cardiovasc Genet. 2015;8(2):343-50 - PMID: 25632026 - PMCID: PMC4406825
Lo J, Rosenberg ES, Fitzgerald ML, Bazner SB, Ihenachor EJ, Hawxhurst V, Borkowska AH, Wei J, Zimmerman CO, Burdo TH, Williams KC, Freeman MW, Grinspoon SK
High-density lipoprotein-mediated cholesterol efflux capacity is improved by treatment with antiretroviral therapy in acute human immunodeficiency virus infection.
Open Forum Infect Dis. 2014;1(3):ofu108 - PMID: 25734176 - PMCID: PMC4324225
Haller JF, Cavallaro P, Hernandez NJ, Dolat L, Soscia SJ, Welti R, Grabowski GA, Fitzgerald ML, Freeman MW
Endogenous ?-glucocerebrosidase activity in Abca12-/-epidermis elevates ceramide levels after topical lipid application but does not restore barrier function.
J Lipid Res. 2013;55(3):493-503 - PMID: 24293640 - PMCID: PMC3934733
Perlstein TS, Goldhaber SZ, Nelson K, Joshi V, Morgan TV, Lesko LJ, Lee JY, Gobburu J, Schoenfeld D, Kucherlapati R, Freeman MW, Creager MA
The Creating an Optimal Warfarin Nomogram (CROWN) Study.
Thromb Haemost. 2011;107(1):59-68 - PMID: 22116191 - PMCID: PMC4133142
Freeman MW, Dervan AP
The path from bench to bedside: considerations before starting the journey.
J Investig Med. 2011;59(5):746-51 - PMID: 21441830 - PMCID: PMC4255460
Zuo Y, Zhuang DZ, Han R, Isaac G, Tobin JJ, McKee M, Welti R, Brissette JL, Fitzgerald ML, Freeman MW
ABCA12 maintains the epidermal lipid permeability barrier by facilitating formation of ceramide linoleic esters.
J Biol Chem. 2008;283(52):36624-35 - PMID: 18957418 - PMCID: PMC2605993

Journal Articles

Jennelle L, Hunegnaw R, Dubrovsky L, Pushkarsky T, Fitzgerald ML, Sviridov D, Popratiloff A, Brichacek B, Bukrinsky M
HIV-1 Protein Nef Inhibits Activity of ATP Binding Cassette Transporter A1 by Targeting Endoplasmic Reticulum Chaperone Calnexin.
J Biol Chem. 2014;289(42):28870-84 - PMID: 25170080 - PMCID: PMC4200247