title: Metabolic assessment of human liver transplants from biopsy samples at the donor and recipient stages using high-resolution magic angle spinning 1H NMR spectroscopy.
abstract: This work presents the first application of high-resolution magic angle spinning (HR-MAS) 1H NMR spectroscopy to human liver biopsy samples, allowing a determination of their metabolic profiles before removal from donors, during cold perfusion, and after implantation into recipients. The assignment of peaks observed in the 1H HR-MAS NMR spectra was aided by the use of two-dimensional J-resolved, TOCSY and 1H-13C HMQC spectra. The spectra were dominated by resonances from triglycerides, phospholipids, and glycogen and from a variety of small molecules including glycerophosphocholine (GPC), glucose, lactate, creatine, acetate, amino acids, and nucleoside-related compounds such as uridine and adenosine. In agreement with histological data obtained on the same biopsies, two of the six livers were found to contain high amounts of triglycerides by NMR spectroscopy, which also indicated that these tissues contained a higher degree of unsaturated lipids and a lower proportion of phospholipids and low molecular weight compounds. Additionally, proton T2 relaxation times indicated two populations of lipids, a higher mobility triglyceride fraction and a lower mobility phospholipid fraction, the proportions of which changed according to the degree of fat content. GPC was found to decrease from the pretransplant to the posttransplant biopsy of all livers except for one with a histologically confirmed high lipid content, and this might represent a biomarker of liver function posttransplantation. NMR signals produced by the liver preservation solution were clearly detected in the cold perfusion stage biopsies of all livers but remained in the posttransplant spectra of only the two livers with a high lipid content and were prominent mainly in the graft that later developed primary graft dysfunction. This study has shown biochemical differences between livers used for transplants that can be related to the degree and type of lipid composition. This technology might therefore provide a novel screening approach for donor organ quality and a means to assess function in the recipient after transplantation.
authors.affiliation: Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Iola F
authors.initials: IF
authors.lastname: Duarte
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Stanley
authors.forename: Elaine
authors.initials: E
authors.lastname: Holmes
authors.forename: John C
authors.initials: JC
authors.lastname: Lindon
authors.forename: Ana M
authors.initials: AM
authors.lastname: Gil
authors.forename: Huiru
authors.initials: H
authors.lastname: Tang
authors.forename: Roxanne
authors.initials: R
authors.lastname: Ferdinand
authors.forename: Claire Gavaghan
authors.initials: CG
authors.lastname: McKee
authors.forename: Jeremy K
authors.initials: JK
authors.lastname: Nicholson
authors.forename: Hector
authors.initials: H
authors.lastname: Vilca-Melendez
authors.forename: Nigel
authors.initials: N
authors.lastname: Heaton
authors.forename: Gerard M
authors.initials: GM
authors.lastname: Murphy
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008099:Liver / Q000737:chemistry* / Q000378:metabolism*; D008110:Liver Extracts / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D016031:Liver Transplantation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014019:Tissue Donors
chemical_list: D008055:Lipids; D008110:Liver Extracts