Neutrophil elastase cleavage of the gC1q domain impairs the EMILIN1-α4β1 integrin interaction, cell adhesion and anti-proliferative activity

Abstract

The extracellular matrix glycoprotein EMILIN1 exerts a wide range of functions mainly associated with its gC1q domain. Besides providing functional significance for adhesion and migration, the direct interaction between α4β1 integrin and EMILIN1-gC1q regulates cell proliferation, transducing net anti-proliferative effects. We have previously demonstrated that EMILIN1 degradation by neutrophil elastase (NE) is a specific mechanism leading to the loss of functions disabling its regulatory properties. In this study we further analysed the proteolytic activity of NE, MMP-3, MMP-9, and MT1-MMP on EMILIN1 and found that MMP-3 and MT1-MMP partially cleaved EMILIN1 but without affecting the functional properties associated with the gC1q domain, whereas NE was able to fully impair the interaction of gC1q with the α4β1 integrin by cleaving this domain outside of the E933 integrin binding site. By a site direct mutagenesis approach we mapped the bond between S913 and R914 residues and selected the NE-resistant R914W mutant still able to interact with the α4β1 integrin after NE treatment. Functional studies showed that NE impaired the EMILIN1-α4β1 integrin interaction by cleaving the gC1q domain in a region crucial for its proper structural conformation, paving the way to better understand NE effects on EMILIN1-cell interaction in pathological context.

Elevated Neutrophil-to-Lymphocyte Ratio Is Associated With Poor Outcomes for Melanoma Patients Treated With PD-1 Inhibitor or Chemotherapy in a Chinese Population

“…In a mouse model of lung adenocarcinoma [Lox-Stop-Stop (LsL)-K-ras], NE can enter tumor cells to directly induce tumor cell proliferation (61). In addition, NE can indirectly promote tumor cell growth and proliferation by inactivating tumor suppressors, such as Elastin Microfibril Interface Located Protein 1 (EMILIN1) and thrombospondin-1 (62,63).…”

Neutrophil elastase in the tumor microenvironment

“…In fact, the loss of tumor suppressor function is a critical step in initiation of many cancers, and neutrophil elastase may contribute to tumor progression in such a manner. For instance, neutrophil elastase-dependent cleavage compromises the tumor suppressor role of EMILIN1 [58, 59]. While extracellular matrix associated EMILIN1 normally inhibits proliferation of leiomyosarcoma cells through engagement of α4/β1 integrins, neutrophil elastase-cleaved EMILIN1 is unable to exert this effect [58, 59].…”

“…For instance, neutrophil elastase-dependent cleavage compromises the tumor suppressor role of EMILIN1 [58, 59]. While extracellular matrix associated EMILIN1 normally inhibits proliferation of leiomyosarcoma cells through engagement of α4/β1 integrins, neutrophil elastase-cleaved EMILIN1 is unable to exert this effect [58, 59]. Furthermore, neutrophil elastase inactivates the anti-tumorigenic factor thrombospondin-1 (Tsp-1), enhancing growth of lung tumors and metastatic melanoma foci in the lung [60].…”

TSPAN9 and EMILIN1 synergistically inhibit the migration and invasion of gastric cancer cells by increasing TSPAN9 expression

“…It is highly expressed in blood vessels, lymphatic vessels and connective tissues of various organs [13]. EMILIN1 has a specifically aligned domain, including a C-terminal gc1q-like globular domain, a latent coiled-a-helical structure, and a N-terminal cysteine-rich domain [14]. Studies have shown that the gc1q homology domain of EMILIN1 can interact with α4β1 integrin, thereby affecting cell adhesion and migration [14].…”

“…EMILIN1 has a specifically aligned domain, including a C-terminal gc1q-like globular domain, a latent coiled-a-helical structure, and a N-terminal cysteine-rich domain [14]. Studies have shown that the gc1q homology domain of EMILIN1 can interact with α4β1 integrin, thereby affecting cell adhesion and migration [14]. What if any role is played by EMILIN1 in cancer remains uncertain.…”