THBD

THBD Full Name

thrombomodulin

THBD Introduction

Thrombomodulin (THBD), also known as CD141, is an integral membrane glycoprotein primarily expressed on the luminal surface of vascular endothelial cells, where it plays a paramount role in maintaining vascular homeostasis. Physiologically, THBD functions as a critical natural anticoagulant and a master regulator of the hemostatic balance. It exerts its primary function by acting as a high-affinity cell-surface receptor for thrombin. Upon binding to THBD, thrombin undergoes a dramatic functional switch: it loses its procoagulant ability to cleave fibrinogen and activate platelets, and instead acquires the capacity to rapidly activate protein C. The activated protein C (aPC), acting in concert with its cofactor protein S, subsequently degrades essential coagulation factors Va and VIIIa, thereby potently halting the coagulation cascade and preventing excessive clot formation.

Figure 1. The protein C activation by the thrombin-thrombomodulin complex and the cytoprotective function of Activated Protein C (APC) in ischemic heart disease and heart failure. (Source: Ren D, et al. 2019)

Beyond its classic anticoagulant function, THBD exerts profound anti-inflammatory, barrier-protective, and cytoprotective effects. It achieves this notably through the activation of thrombin-activatable fibrinolysis inhibitor (TAFI) and the direct sequestration of pro-inflammatory mediators, such as HMGB1. Consequently, the downregulation, shedding, or genetic mutation of THBD is intimately linked to a wide spectrum of severe hematological and vascular disorders. Pathologically, a loss of THBD function disrupts the delicate hemostatic balance, heavily predisposing individuals to thromboembolic events such as deep vein thrombosis and pulmonary embolism.

Furthermore, mutations within the THBD gene are causally associated with atypical hemolytic uremic syndrome (aHUS), a rare, life-threatening condition characterized by systemic thrombotic microangiopathy and severe renal impairment. In clinical diagnostics, soluble THBD (sTM), which is shed from the endothelium during vascular injury, serves as a highly valuable circulating biomarker for conditions like sepsis, atherosclerosis, and severe inflammatory syndromes, accurately reflecting the extent of endothelial dysfunction and vascular damage.

Alternate Names for THBD

THBD; thrombomodulin; TM; THRM; AHUS6; BDCA3; CD141; THPH12; fetomodulin; CD141 antigen;

• 1. Ren D, et al. The Cardioprotective Signaling Activity of Activated Protein C in Heart Failure and Ischemic Heart Diseases. Int J Mol Sci. 2019 Apr 10;20(7):1762.
  2. Loghmani H, et al. Exploring traditional and nontraditional roles for thrombomodulin. Blood. 2018 Jul 12;132(2):148-158.