Skip to Content
Merck
  • Genuine selective caspase-2 inhibition with new irreversible small peptidomimetics.

Genuine selective caspase-2 inhibition with new irreversible small peptidomimetics.

Cell death & disease (2022-11-16)
Elodie Bosc, Julie Anastasie, Feryel Soualmia, Pascale Coric, Ju Youn Kim, Lily Q Wang, Gullen Lacin, Kaitao Zhao, Ronak Patel, Eric Duplus, Philippe Tixador, Andrew A Sproul, Bernard Brugg, Michelle Reboud-Ravaux, Carol M Troy, Michael L Shelanski, Serge Bouaziz, Michael Karin, Chahrazade El Amri, Etienne D Jacotot
ABSTRACT

Caspase-2 (Casp2) is a promising therapeutic target in several human diseases, including nonalcoholic steatohepatitis (NASH) and Alzheimer's disease (AD). However, the design of an active-site-directed inhibitor selective to individual caspase family members is challenging because caspases have extremely similar active sites. Here we present new peptidomimetics derived from the VDVAD pentapeptide structure, harboring non-natural modifications at the P2 position and an irreversible warhead. Enzyme kinetics show that these new compounds, such as LJ2 or its specific isomers LJ2a, and LJ3a, strongly and irreversibly inhibit Casp2 with genuine selectivity. In agreement with the established role of Casp2 in cellular stress responses, LJ2 inhibits cell death induced by microtubule destabilization or hydroxamic acid-based deacetylase inhibition. The most potent peptidomimetic, LJ2a, inhibits human Casp2 with a remarkably high inactivation rate (k3/Ki ~5,500,000 M-1 s-1), and the most selective inhibitor, LJ3a, has close to a 1000 times higher inactivation rate on Casp2 as compared to Casp3. Structural analysis of LJ3a shows that the spatial configuration of Cα at the P2 position determines inhibitor efficacy. In transfected human cell lines overexpressing site-1 protease (S1P), sterol regulatory element-binding protein 2 (SREBP2) and Casp2, LJ2a and LJ3a fully inhibit Casp2-mediated S1P cleavage and thus SREBP2 activation, suggesting a potential to prevent NASH development. Furthermore, in primary hippocampal neurons treated with β-amyloid oligomers, submicromolar concentrations of LJ2a and of LJ3a prevent synapse loss, indicating a potential for further investigations in AD treatment.

MATERIALS
Product Number
Brand
Product Description

Millipore
ANTI-FLAG® antibody produced in rabbit, affinity isolated antibody, buffered aqueous solution
Sigma-Aldrich
Anti-MDM2 Antibody, clone IF2, clone IF2, from mouse
Sigma-Aldrich
Deoxyribonuclease I from bovine pancreas, Type IV, lyophilized powder, ≥2,000 Kunitz units/mg protein
Sigma-Aldrich
Anti-MAP2 Antibody, clone AP20, Alexa Fluor 555 Conjugate, clone AP20, from mouse, ALEXA FLUOR 555
Sigma-Aldrich
Anti-Beta III Tubulin Antibody, Alexa Fluor 488 Conjugate | AB15708A4, from rabbit, ALEXA FLUOR 488