Leeds Institute of Cardiovascular & Metabolic Medicine, University of Leeds, Leeds, West Yorkshire, United Kingdom.
Department of Medicine, Hematology and Oncology Division, CWRU School of Medicine, Cleveland, OH, USA.
J Thromb Haemost. 2023 Apr;21(4):814-827. doi: 10.1016/j.jtha.2022.12.015. Epub 2022 Dec 27.
Human serum albumin (HSA) is the most abundant plasma protein and is sensitive to glycation in vivo. The chronic hyperglycemic conditions in patients with diabetes mellitus (DM) induce a nonenzymatic Maillard reaction that denatures plasma proteins and forms advanced glycation end products (AGEs). HSA-AGE is a prevalent misfolded protein in patients with DM and is associated with factor XII activation and downstream proinflammatory kallikrein-kinin system activity without any associated procoagulant activity of the intrinsic pathway.
This study aimed to determine the relevance of HSA-AGE toward diabetic pathophysiology.
The plasma obtained from patients with DM and euglycemic volunteers was probed for activation of FXII, prekallikrein (PK), and cleaved high-molecular-weight kininogen by immunoblotting. Constitutive plasma kallikrein activity was determined via chromogenic assay. Activation and kinetic modulation of FXII, PK, FXI, FIX, and FX via in vitro-generated HSA-AGE were explored using chromogenic assays, plasma-clotting assays, and an in vitro flow model using whole blood.
Plasma obtained from patients with DM contained increased plasma AGEs, activated FXIIa, and resultant cleaved cleaved high-molecular-weight kininogen. Elevated constitutive plasma kallikrein enzymatic activity was identified, which positively correlated with glycated hemoglobin levels, representing the first evidence of this phenomenon. HSA-AGE, generated in vitro, triggered FXIIa-dependent PK activation but limited the intrinsic coagulation pathway activation by inhibiting FXIa and FIXa-dependent FX activation in plasma.
These data indicate a proinflammatory role of HSA-AGEs in the pathophysiology of DM via FXII and kallikrein-kinin system activation. A procoagulant effect of FXII activation was lost through the inhibition of FXIa and FIXa-dependent FX activation by HSA-AGEs.
人血清白蛋白（HSA）是最丰富的血浆蛋白，并且对体内糖基化敏感。糖尿病患者的慢性高血糖状态会引起非酶促美拉德反应，使血浆蛋白变性并形成晚期糖基化终产物（AGEs）。HSA-AGE 是糖尿病患者中普遍存在的错误折叠蛋白，与因子 XII 的激活和下游促炎激肽释放酶-激肽系统活性有关，而没有内在途径的任何相关促凝活性。
本研究旨在确定 HSA-AGE 与糖尿病病理生理学的相关性。
通过免疫印迹法探测来自糖尿病患者和血糖正常志愿者的血浆中 FXII、前激肽释放酶（PK）和裂解高分子量激肽原的激活情况。通过显色测定法确定组成性血浆激肽酶活性。通过显色测定法、血浆凝固测定法和使用全血的体外流动模型，探索体外生成的 HSA-AGE 对 FXII、PK、FXI、FIX 和 FX 的激活和动力学调节。
来自糖尿病患者的血浆中含有增加的血浆 AGEs、激活的 FXIIa 和由此产生的裂解高分子量激肽原。鉴定出升高的组成性血浆激肽酶酶活性，其与糖化血红蛋白水平呈正相关，这代表了这种现象的首次证据。体外生成的 HSA-AGE 触发 FXIIa 依赖性 PK 激活，但通过抑制 FXIa 和 FIXa 依赖性 FX 激活来限制内在凝血途径的激活。
这些数据表明 HSA-AGEs 通过 FXII 和激肽释放酶-激肽系统的激活在糖尿病的病理生理学中发挥促炎作用。通过 HSA-AGE 抑制 FXIa 和 FIXa 依赖性 FX 激活，FXII 激活的促凝作用丧失。
