Cathepsin K cleavage of Angiopoietin-2 creates detrimental Tie2 antagonist fragments in sepsis

Takashi Suzuki; Erik Loyde; Sara Chen; Valerie Etzrodt; Temitayo O. Idowu; Amanda J. Clark; Marie Christelle Saade; Brenda Mendoza Flores; Shulin Lu; Gabriel Birrane; Vamsidhara Vemireddy; Benjamin Seeliger; Sascha David; Samir M. Parikh

doi:10.1172/JCI174135

Cathepsin K cleavage of Angiopoietin-2 creates detrimental Tie2 antagonist fragments in sepsis

Takashi Suzuki,¹ Erik Loyde,¹ Sara Chen,² Valerie Etzrodt,¹ Temitayo O. Idowu,¹ Amanda J. Clark,¹ Marie Christelle Saade,¹ Brenda Mendoza Flores,¹ Shulin Lu,² Gabriel Birrane,³ Vamsidhara Vemireddy,¹ Benjamin Seeliger,⁴ Sascha David,⁵ and Samir M. Parikh¹

Published March 3, 2025 - More info

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Abstract

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, 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.

Cathepsin K cleavage of Angiopoietin-2 creates detrimental Tie2 antagonist fragments in sepsis

Takashi Suzuki,¹ Erik Loyde,¹ Sara Chen,² Valerie Etzrodt,¹ Temitayo O. Idowu,¹ Amanda J. Clark,¹ Marie Christelle Saade,¹ Brenda Mendoza Flores,¹ Shulin Lu,² Gabriel Birrane,³ Vamsidhara Vemireddy,¹ Benjamin Seeliger,⁴ Sascha David,⁵ and Samir M. Parikh¹

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Cathepsin K cleavage of Angiopoietin-2 creates detrimental Tie2 antagonist fragments in sepsis

Takashi Suzuki,1 Erik Loyde,1 Sara Chen,2 Valerie Etzrodt,1 Temitayo O. Idowu,1 Amanda J. Clark,1 Marie Christelle Saade,1 Brenda Mendoza Flores,1 Shulin Lu,2 Gabriel Birrane,3 Vamsidhara Vemireddy,1 Benjamin Seeliger,4 Sascha David,5 and Samir M. Parikh1

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Takashi Suzuki,¹ Erik Loyde,¹ Sara Chen,² Valerie Etzrodt,¹ Temitayo O. Idowu,¹ Amanda J. Clark,¹ Marie Christelle Saade,¹ Brenda Mendoza Flores,¹ Shulin Lu,² Gabriel Birrane,³ Vamsidhara Vemireddy,¹ Benjamin Seeliger,⁴ Sascha David,⁵ and Samir M. Parikh¹