Suzuki Takashi, Loyde Erik, Chen Sara, Etzrodt Valerie, Idowu Temitayo O, Clark Amanda J, Saade Marie Christelle, Flores Brenda Mendoza, Lu Shulin, Birrane Gabriel, Vemireddy Vamsidhara, Seeliger Benjamin, David Sascha, Parikh Samir M
Division of Nephrology, Department of Medicine, UT Southwestern Medical Center, Dallas, Texas, USA.
Center for Vascular Biology Research, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
J Clin Invest. 2025 Mar 3;135(8). doi: 10.1172/JCI174135. eCollection 2025 Apr 15.
Elevated angiopoietin-2 is associated with diverse inflammatory conditions, including sepsis, a leading global cause of mortality. During inflammation, angiopoietin-2 antagonizes the endothelium-enriched receptor Tie2 to destabilize the vasculature. In other contexts, angiopoietin-2 stimulates Tie2. The basis for context-dependent antagonism remains incompletely understood. Here, we show that inflammation-induced proteolytic cleavage of angiopoietin-2 converts this ligand from Tie2 agonist to antagonist. Conditioned media from stimulated macrophages induced endothelial angiopoietin-2 secretion. Unexpectedly, this was associated with reduction of the 75 kDa full-length protein and appearance of new 25 and 50 kDa C-terminal fragments. Peptide sequencing proposed cathepsin K as a candidate protease. Cathepsin K was necessary and sufficient to cleave angiopoietin-2. Recombinant 25 and 50 kDa angiopoietin-2 fragments (cANGPT225 and cANGPT250) bound and antagonized Tie2. Cathepsin K inhibition with the phase 3 small-molecule inhibitor odanacatib improved survival in distinct murine sepsis models. Full-length angiopoietin-2 enhanced survival in endotoxemic mice administered odanacatib and, conversely, increased mortality in the drug's absence. Odanacatib's benefit was reversed by heterologous cANGPT225. Septic humans accumulated circulating angiopoietin-2 fragments, which were associated with adverse outcomes. These results identify cathepsin K as a candidate marker of sepsis and a proteolytic mechanism for the conversion of angiopoietin-2 from Tie2 agonist to antagonist, with therapeutic implications for inflammatory conditions associated with angiopoietin-2 induction.
血管生成素-2升高与多种炎症性疾病相关，包括败血症，败血症是全球主要的死亡原因。在炎症过程中，血管生成素-2拮抗富含内皮细胞的受体Tie2，使脉管系统不稳定。在其他情况下，血管生成素-2刺激Tie2。这种依赖于环境的拮抗作用的基础仍未完全了解。在这里，我们表明炎症诱导的血管生成素-2蛋白水解切割将这种配体从Tie2激动剂转变为拮抗剂。刺激的巨噬细胞的条件培养基诱导内皮血管生成素-2分泌。出乎意料的是，这与75 kDa全长蛋白的减少和新的25 kDa和50 kDa C末端片段的出现有关。肽测序提出组织蛋白酶K作为候选蛋白酶。组织蛋白酶K是切割血管生成素-2所必需且足够的。重组25 kDa和50 kDa血管生成素-2片段（cANGPT225和cANGPT250）结合并拮抗Tie2。用3期小分子抑制剂奥达卡替抑制组织蛋白酶K可提高不同小鼠败血症模型的存活率。全长血管生成素-2可提高给予奥达卡替的内毒素血症小鼠的存活率，相反，在没有该药物的情况下会增加死亡率。异源cANGPT225可逆转奥达卡替的益处。败血症患者体内积累循环血管生成素-2片段，这与不良预后相关。这些结果确定组织蛋白酶K为败血症的候选标志物，以及血管生成素-2从Tie2激动剂转变为拮抗剂的蛋白水解机制，对与血管生成素-2诱导相关的炎症性疾病具有治疗意义。
