Identification of Two Sulfated Cholesterol Metabolites Found in the Urine of a Patient with Niemann–Pick Disease Type C as Novel Candidate Diagnostic Markers

Abstract

In the urine of a Niemann-Pick disease type C (NPC) patient, we have identi ed three characteristic intense peaks that have not been observed in the urine of a 3β-hydroxysteroid-Δ 5 -C 27 -steroid dehydrogenase de ciency patient or a healthy infant and adult. Based on accurate masses of the protonated molecules, we focused on two of them as candidate NPC diagnostic markers. Two synthesized authentic preparations agreed with the two compounds found in NPC patient urine in regard to both chromatographic behavior and accurate masses of the deprotonated molecules. Moreover, the isotopic patterns of the deprotonated molecules, twin peaks unique to the sulfur-containing compounds appearing in their second isotope positions, and accurate masses of product ions observed at m/z 97 also agreed between the target compounds and authentic preparations. We identi ed the two compounds as the sulfated cholesterol metabolites as 3β-sulfooxy-7β-hydroxy-5-cholen-24-oic acid and 3β-sulfooxy-7-oxo-5-cholen-24-oic acid.ese two compounds represent more promising candidate diagnostic markers for NPC diagnosis than three other candidates that are multiple conjugates of cholesterol metabolites, 3β-sulfooxy-7β-N-acetylglucosaminyl-5-cholen-24-oic acid and its glycine and taurine conjugates, although we have reported an analytical method for determining the urinary levels of these compounds using liquid chromatography/electrospray ionization tandem mass spectrometry, because of their lack of N-acetylglucosamine conjugation.

Elevation of plasma lysosphingomyelin-509 and urinary bile acid metabolite in Niemann-Pick disease type C-affected individuals

“…Bile acid metabolites, which are a series of compounds that originate in bile acids, have received much attention as biomarkers for NPC [ [10] , [11] , [12] , [13] , [14] , 26 , 27 ]. A milestone study was performed by Alvelius et al, which showed that bile acid metabolites in NPC-affected individuals were elevated by GC–MS [ 10 ].…”

Identification and Evaluation of Biomarkers for Niemann-Pick Disease Type C Based on Chemical Analysis Techniques

“…A simultaneous analytical method for SNAG-Δ 5 -CA, SNAG-Δ 5 -CG, SNAG-Δ 5 -CT, S7B-Δ 5 -CA, and S7O-Δ 5 -CA in urine was developed using LC/MS/MS, and its diagnostic performance for NPC was evaluated [83]. Along with other previous reports [66,67,81,82], a LC/ESI-MS/MS system equipped with a column switching system was used. A Capcell pak C18 BB-H (Osaka soda, Osaka, Japan) was used as an analytical column and OASIS HLB (Waters) was used as a trapping column for online pretreatment with 20 mM ammonium acetate buffer (pH 5.5) as mobile phase A and methanol as mobile phase B.…”

Investigation of diagnostic performance of five urinary cholesterol metabolites for Niemann-Pick disease type C

“…SNAG-Δ 5 -CA, SNAG-Δ 5 -CG, SNAG-Δ 5 -CT, S7B-Δ 5 -CA, S7O-Δ 5 -CA, and 3β-sulfooxy-7β-hydroxy-23-nor-5-cholenoic acid (as an internal standard (IS)) were synthesized as described in previous reports (the structures are shown in the Fig. 1) (13)(14)(15). Ultrapure water was prepared with a PURELAB ultra apparatus (Organo Co.…”

“…However, several patients with NPC had extremely low concentrations of the relevant metabolites and false-negatives. Thus, a comprehensive analysis method was used to search for other biomarker candidates (12), which yielded two strongly detected metabolite peaks in urine of patients with NPC, 3β-sulfooxy-7β-hydroxy-5-cholenoic acid (S7B-Δ 5 -CA) and 3β-sulfooxy-7-oxo-5-cholenoic acid (S7O-Δ 5 -CA) (13). In this study, we evaluated the NPC diagnostic marker performance of five urinary conjugated cholesterol metabolites.…”