Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida, USA.
Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
Magn Reson Chem. 2023 Dec;61(12):748-758. doi: 10.1002/mrc.5382. Epub 2023 Jul 22.
In a clinical setting, ex vivo perfusions are routinely used to maintain and assess organ viability prior to transplants. Organ perfusions are also a model system to examine metabolic flux while retaining the local physiological structure, with significant success using hyperpolarized (HP) C NMR in this context. We use a novel exocrine pancreas perfusion technique via the common bile duct to assess acinar cell metabolism with HP [1- C]pyruvate. The exocrine component of the pancreas produces digestive enzymes through the ductal system and is often neglected in research on the pancreas. Real-time production of [1- C]lactate, [1- C]alanine, [1- C]malate, [4- C]malate, [1- C]aspartate, and H CO was detected. The appearance of these resonances indicates flux through both pyruvate dehydrogenase and pyruvate carboxylase. We studied excised pancreata from C57BL/6J mice and NOD.Rag1 .AI4 mice, a commonly used model of Type 1 Diabetes (T1D). Pancreata from the T1D mice displayed increased lactate to alanine ratio without changes in oxygen consumption, signifying increased cytosolic NADH levels. The mass isotopologue analysis of the extracted pancreas tissue using gas chromatography-mass spectrometry revealed confirmatory C enrichment in multiple TCA cycle metabolites that are products of pyruvate carboxylation. The methodology presented here has the potential to provide insight into mechanisms underlying several pancreatic diseases, such as diabetes, pancreatitis, and pancreatic cancer.
在临床环境中,常通过离体灌注来维持和评估移植前器官的活力。器官灌注也是一种检查代谢通量的模型系统,同时保留局部生理结构,在这种情况下,使用极化(HP) 13 C NMR 取得了显著成功。我们使用一种新颖的通过胆总管的外分泌胰腺灌注技术,用 HP [1- 13 C]丙酮酸评估胰腺细胞的代谢。胰腺的外分泌部分通过导管系统产生消化酶,在胰腺研究中经常被忽视。实时检测到[1- 13 C]乳酸盐、[1- 13 C]丙氨酸、[1- 13 C]苹果酸、[4- 13 C]苹果酸、[1- 13 C]天冬氨酸和 H CO 3 的产生。这些共振的出现表明通过丙酮酸脱氢酶和丙酮酸羧化酶的通量。我们研究了 C57BL/6J 小鼠和 NOD.Rag1.AI4 小鼠(1 型糖尿病的常用模型)的离体胰腺。来自 T1D 小鼠的胰腺显示出增加的乳酸盐对丙氨酸的比值,而耗氧量没有变化,表明细胞质 NADH 水平增加。使用气相色谱-质谱联用仪对提取的胰腺组织进行的质量同量异位素分析显示,多个 TCA 循环代谢物的 13 C 富集得到证实,这些代谢物是丙酮酸羧化的产物。这里提出的方法有可能深入了解几种胰腺疾病(如糖尿病、胰腺炎和胰腺癌)的潜在机制。