Global Metabolomic and Isobaric Tagging Capillary Liquid Chromatography–Tandem Mass Spectrometry Approaches for Uncovering Pathway Dysfunction in Diabetic Mouse Aorta

Despite
the prevalence of diabetes and the global health risks
it poses, the biochemical pathogenesis of diabetic complications remains
poorly understood with few effective therapies. This study employs
capillary liquid chromatography (capLC) and tandem mass spectrometry
(MS/MS) in conjunction with both global metabolomics and isobaric
tags specific to amines and carbonyls to probe aortic metabolic content
in diabetic mice with hyperglycemia, hyperlipidemia, hypertension,
and stenotic vascular damage. Using these combined techniques, metabolites
well-characterized in diabetes as well as novel pathways were investigated.
A total of 53 986 features were detected, 719 compounds were
identified as having significant fold changes (thresholds ≥2
or ≤0.5), and 48 metabolic pathways were found to be altered
with at least 2 metabolite hits in diabetic samples. Pathways related
to carbonyl stress, carbohydrate metabolism, and amino acid metabolism
showed the greatest number of metabolite changes. Three novel pathways
with previously limited or undescribed roles in diabetic complicationsvitamin
B6, propanoate, and butanoate metabolismwere also shown to
be altered in multiple points along the pathway. These discoveries
support the theory that diabetic vascular complications arise from
the interplay of a myriad of metabolic pathways in conjunction with
oxidative and carbonyl stress, which may provide not only new and
much needed biomarkers but also insights into novel therapeutic targets.

尽管糖尿病发病率居高不下且带来全球性健康风险，但糖尿病并发症的生化发病机制仍鲜为人知，且有效治疗手段匮乏。本研究采用毛细管液相色谱（capillary liquid chromatography, capLC）结合串联质谱（tandem mass spectrometry, MS/MS），联合全局代谢组学以及针对胺类与羰基类化合物的特异性等压标签，对同时患有高血糖、高血脂、高血压及血管狭窄损伤的糖尿病小鼠的主动脉代谢物含量进行探究。借助上述联合技术，本研究对糖尿病中已被充分表征的代谢物，以及全新代谢通路展开了探究。本研究共检测到53986个特征峰，鉴定出719种具有显著倍数变化（阈值≥2或≤0.5）的化合物，且在糖尿病小鼠样本中发现48条代谢通路发生改变，且每条通路至少匹配到2种代谢物。羰基应激、碳水化合物代谢以及氨基酸代谢相关通路的代谢物变化数量最多。此前在糖尿病并发症中作用有限或未被阐明的三条全新代谢通路——维生素B6代谢、丙酸代谢及丁酸代谢——也被证实其通路内多个位点发生了改变。上述发现支持了糖尿病血管并发症源于大量代谢通路与氧化应激、羰基应激相互作用的理论，该研究不仅可为临床提供亟需的新型生物标志物，还可为开发全新治疗靶点提供思路。