title: Metabolism of (13)C5-hydroxyproline in mouse models of Primary Hyperoxaluria and its inhibition by RNAi therapeutics targeting liver glycolate oxidase and hydroxyproline dehydrogenase.
abstract: Excessive endogenous oxalate synthesis can result in calcium oxalate kidney stone formation and renal failure. Hydroxyproline catabolism in the liver and kidney contributes to endogenous oxalate production in mammals. To quantify this contribution we have infused Wt mice, Agxt KO mice deficient in liver alanine:glyoxylate aminotransferase, and Grhpr KO mice deficient in glyoxylate reductase, with (13)C5-hydroxyproline. The contribution of hydroxyproline metabolism to urinary oxalate excretion in Wt mice was 22±2%, 42±8% in Agxt KO mice, and 36%±9% in Grhpr KO mice. To determine if blocking steps in hydroxyproline and glycolate metabolism would decrease urinary oxalate excretion, mice were injected with siRNA targeting the liver enzymes glycolate oxidase and hydroxyproline dehydrogenase. These siRNAs decreased the expression of both enzymes and reduced urinary oxalate excretion in Agxt KO mice, when compared to mice infused with a luciferase control preparation. These results suggest that siRNA approaches could be useful for decreasing the oxalate burden on the kidney in individuals with Primary Hyperoxaluria.
authors.affiliation: Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
authors.forename: Xingsheng
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
authors.forename: John
authors.initials: J
authors.lastname: Knight
authors.affiliation: Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
authors.forename: Sonia
authors.initials: S
authors.lastname: Fargue
authors.affiliation: Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
authors.forename: Brianna
authors.initials: B
authors.lastname: Buchalski
authors.affiliation: Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Guan
authors.affiliation: Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Inscho
authors.affiliation: Alnylam Pharmaceuticals, Cambridge, MA, United States.
authors.forename: Abigail
authors.initials: A
authors.lastname: Liebow
authors.affiliation: Alnylam Pharmaceuticals, Cambridge, MA, United States.
authors.forename: Kevin
authors.initials: K
authors.lastname: Fitzgerald
authors.affiliation: Alnylam Pharmaceuticals, Cambridge, MA, United States.
authors.forename: William
authors.initials: W
authors.lastname: Querbes
authors.affiliation: Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
authors.forename: W
authors.initials: W
authors.lastname: Todd Lowther
authors.affiliation: Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, United States. Electronic address: rholmes@uab.edu.
authors.forename: Ross P
authors.initials: RP
authors.lastname: Holmes
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D006909:Hydroxyproline / Q000378:metabolism*; D006960:Hyperoxaluria, Primary / Q000235:genetics* / Q000378:metabolism / Q000628:therapy*; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010070:Oxalates / Q000378:metabolism; D011394:Proline Oxidase / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000627:therapeutic use; D000067492:RNAi Therapeutics / Q000379:methods
chemical_list: D010070:Oxalates; D034741:RNA, Small Interfering; D000429:Alcohol Oxidoreductases; C020821:glycollate oxidase; D011394:Proline Oxidase; D006909:Hydroxyproline