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Mechanisms of pathogenic effects of eosinophil cationic protein and eosinophil‐derived neurotoxin on human keratinocytes
Author(s) -
Amber Kyle T.,
Chernyavsky Alex,
Agnoletti Arianna F.,
Cozzani Emanuele,
Grando Sergei A.
Publication year - 2018
Publication title -
experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 96
eISSN - 1600-0625
pISSN - 0906-6705
DOI - 10.1111/exd.13782
Subject(s) - eosinophil cationic protein , keratinocyte , eosinophil , apoptosis , eotaxin , chemistry , eosinophil peroxidase , microbiology and biotechnology , chemokine , immunology , cxcl10 , biology , inflammation , in vitro , biochemistry , asthma
Cutaneous deposition of eosinophil degranulation proteins is a major feature of eosinophil‐rich cutaneous diseases including bullous pemphigoid ( BP ). We sought to better understand the effect of two of these proteins – eosinophil cationic protein ( ECP ) and eosinophil‐derived neurotoxin ( EDN ), on human keratinocytes using the Het‐1A cell line. To evaluate expression of key cytokines and chemokines observed in BP as well as metal metalloprotease 9 ( MMP 9), we performed qPCR and in‐cell Western assays on cells treated with either ECP or EDN . We further evaluated the effect of ECP and EDN on keratinocyte survival, generation of reactive oxygen species ( ROS ) and apoptosis. Lastly, we assessed ECP and EDN 's ability to induce keratinocyte detachment from provisional matrix. Treatment of keratinocytes with ECP and EDN resulted in significant increases in IL ‐5, eotaxin‐1 and CCL 5 ( RANTES ) expression at both mRNA and protein levels, but not IL ‐17 or IL ‐31. ECP and EDN also upregulate MMP 9 production. Inhibiting MMP 9, we confirmed that keratinocyte expression of IL ‐5, eotaxin‐1 and RANTES was independent from MMP 9. Both ECP and EDN were cytotoxic to keratinocytes, inducing ROS formation and apoptosis through a mitochondrion‐dependent pathway as evidenced by results of terminal deoxynucleotidyl transferase dUTP nick‐end labelling ( TUNEL ) and cytochrome c release assays, respectively. ECP but not EDN led to significant keratinocyte detachment from provisional matrix. These findings demonstrate that the pathogenic effects of ECP and EDN in BP may result from their direct action on keratinocytes, and as such may became a target for future therapies in eosinophil‐rich cutaneous diseases.