Getting a cure is pretty difficult, but it starts from doing research. It starts from understanding the basic processes, the scientific processes, the physiological processes. So what we try to do is to uncover enough basic science that we gain insights into how the human body…works.
Dr. Freeze focuses on identifying the genetic causes of Congenital Disorders of Glycosylation (CDG).
Dr. Freeze earned his Ph.D. from the University of California, San Diego.
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Targeted polymerase chain reaction-based enrichment and next generation sequencing for diagnostic testing of congenital disorders of glycosylation.
Jones MA, Bhide S, Chin E, Ng BG, Rhodenizer D, Zhang VW, Sun JJ, Tanner A, Freeze HH, Hegde MR
Genet Med. 2011 Nov;13(11):921-32
Golgi glycosylation and human inherited diseases.
Freeze HH, Ng BG
Cold Spring Harb Perspect Biol. 2011 Sep;3(9):a005371
Mannose efflux from the cells: a potential source of mannose in blood.
Sharma V, Freeze HH
J Biol Chem. 2011 Mar 25;286(12):10193-200
SRD5A3 is required for converting polyprenol to dolichol and is mutated in a congenital glycosylation disorder.
Cantagrel V, Lefeber DJ, Ng BG, Guan Z, Silhavy JL, Bielas SL, Lehle L, Hombauer H, Adamowicz M, Swiezewska E, De Brouwer AP, Blümel P, Sykut-Cegielska J, Houliston S, Swistun D, Ali BR, Dobyns WB, Babovic-Vuksanovic D, van Bokhoven H, Wevers RA, Raetz CR, Freeze HH, Morava E, Al-Gazali L, Gleeson JG
Cell. 2010 Jul 23;142(2):203-17
Using heparin therapy to reverse protein-losing enteropathy in a patient with CDG-Ib.
Liem YS, Bode L, Freeze HH, Leebeek FW, Zandbergen AA, Paul Wilson J
Nat Clin Pract Gastroenterol Hepatol. 2008 Apr;5(4):220-4
Heparan sulfate and syndecan-1 are essential in maintaining murine and human intestinal epithelial barrier function.
Bode L, Salvestrini C, Park PW, Li JP, Esko JD, Yamaguchi Y, Murch S, Freeze HH
J Clin Invest. 2008 Jan;118(1):229-38
COG8 deficiency causes new congenital disorder of glycosylation type IIh.
Kranz C, Ng BG, Sun L, Sharma V, Eklund EA, Miura Y, Ungar D, Lupashin V, Winkel RD, Cipollo JF, Costello CE, Loh E, Hong W, Freeze HH
Hum Mol Genet. 2007 Apr 1;16(7):731-41
Genetic defects in the human glycome.
Nat Rev Genet. 2006 Jul;7(7):537-51
Heparan sulfate plays a central role in a dynamic in vitro model of protein-losing enteropathy.
Bode L, Murch S, Freeze HH
J Biol Chem. 2006 Mar 24;281(12):7809-15
Ablation of mouse phosphomannose isomerase (Mpi) causes mannose 6-phosphate accumulation, toxicity, and embryonic lethality.
DeRossi C, Bode L, Eklund EA, Zhang F, Davis JA, Westphal V, Wang L, Borowsky AD, Freeze HH
J Biol Chem. 2006 Mar 3;281(9):5916-27
Carboxylated glycans mediate colitis through activation of NF-kappa B.
Srikrishna G, Turovskaya O, Shaikh R, Newlin R, Foell D, Murch S, Kronenberg M, Freeze HH
J Immunol. 2005 Oct 15;175(8):5412-22
Mutation of the COG complex subunit gene COG7 causes a lethal congenital disorder.
Wu X, Steet RA, Bohorov O, Bakker J, Newell J, Krieger M, Spaapen L, Kornfeld S, Freeze HH
Nat Med. 2004 May;10(5):518-23
Hudson Freeze's Research Focus
Congenital Disorders of Glycosylation, Glycosylation-Related Disorders, Crohn’s Disease (Colitis)
Watch Dr. Freeze describe his research
Dr. Freeze’s research focuses on the pathology resulting from faulty glycosylation, the process of adding carbohydrate (sugar) chains to proteins and lipids. Carbohydrates are required for proper secretion and targeting of thousands of proteins – an often overlooked fact of biology. He is driven by the search for novel therapeutics to treat patients with mutations leading to glycosylation defects called Congenital Disorders of Glycosylation (CDG).
Hudson Freeze's Research Report
Glycosylation: An Essential Function
The entire cell surface is coated with sugars in complex chains that promote (or sometimes interfere) with cell-to-cell communication. These sugar chains are first attached to proteins deep inside the cell where they help them get into shape for their jobs. As the proteins percolate toward to cell surface, the sugar chains are sculpted for specific needs. This entire process, called glycosylation, recruits a force of more than 500 genes for this job. The Freeze lab works on several facets of glycosylation, all of them with an eye toward therapeutic applications for diseases that impair the functions of these critical genes.
Human Glycosylation Disorders
One of our major areas is a group of inherited diseases is called Congenital Disorders of Glycosylation (CDG). Today we know of defects in over 50 genes compared to just 3, only 15 years ago. Patients with these diseases have highly variable mental and motor developmental delay, seizures, failure to grow, hypoglycemia (low blood sugar), clotting and digestion abnormalities, to name just a few. These are rare disorders have over 1000 known patients worldwide, but it is likely that many remain undiagnosed. Physicians are becoming more aware of glycosylation disorders in general, and basic scientists continue to discover sugar chains at the helm of many basic metabolic processes. Defective glycosylation is also known to cause several types of muscular dystrophy. Figure 1 shows the explosive growth in the number of different diseases caused by defective glycosylation. In Figure 2 and the film clip, Harrison Ford poses a few questions for us. Rocket Williams reaches out to us in Figure 3.
The Freeze lab identifies new glycosylation disorders and tries to understand how these defects cause the disease manifestations. Defects occur in genes that activate and transport sugars, assemble them into glycans an remodel them. Some also traffic and distribute the glycosylation machinery within cells. Ongoing collaborations with academic physicians provide a steady flow of new patients for analysis. Since very few laboratories in the United States work on CDG, we are developing new molecular diagnostic methods to handle the increasing number of patients. With the help of generous philanthropic support, we are seeking ways to supplement the depleted glycosylation pathways in patients.
Some patients suffer from an often-lethal condition called protein-losing enteropathy (PLE), where blood proteins leak through the intestine, causing massive fluid imbalance. Some CDG patients and children who have had (Fontan) corrective surgery to mend congenital heart defects sometimes develop PLE months to years after their surgery. Its basis, and why PLE strikes only certain children is a mystery. Aided by the Children¹s Hearts Fund, the lab focuses on understanding how key molecules and environmental insults interact to drive PLE. We used some of these insights to provide a therapy for one young adult with PLE and contribute to ongoing early clinical treatment trials using a modified form of heparin.
Inflammation and Cancer
The other major focus in the Freeze lab is a new facet of how an unusual sugar chain modification is involved in inflammation including Crohn's disease, ulcerative colitis and cancer. A monoclonal antibody against an unusual sugar chain modification, is a potential therapy for inflammatory-related diseases.
A newly funded grant from the California Institute for Regenerative Medicine (CIRM) will explore critical changes in glycosylation that accompany the transition of human embyronic stem cells into neural precursor cells and then differentiate to become neurons, astrocytes, and oligodendrocytes. A collaborative project with Emory University will also explore the basis of abnormal glycosylation seen in patients with galactosemia.
About Hudson Freeze
Dr. Freeze earned his Ph.D. from the University of California, San Diego in 1976. Subsequently he held fellowships in Biology, Medicine and Neurosciences later joined the faculty at the same institution. In 1988 Dr. Freeze was recruited to Sanford-Burnham Medical Research Institute.