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Cathepsin L plays an active role in involution of the mouse mammary gland
Author(s) -
Burke Michael A.,
Hutter Dorothy,
Reshamwala Rita P.,
Knepper Janice E.
Publication year - 2003
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.10313
Subject(s) - involution (esoterism) , biology , cathepsin d , cathepsin , medicine , mammary gland , endocrinology , cathepsin l , weaning , cathepsin b , cathepsin e , in situ hybridization , cytoplasm , immunohistochemistry , messenger rna , microbiology and biotechnology , enzyme , immunology , biochemistry , cathepsin o , gene , consciousness , genetics , cancer , neuroscience , breast cancer
Involution of the mammary gland after weaning occurs in two stages. The first stage is reversible, whereas the second stage is characterized by the irreversible collapse of the alveolar structure. A differential display analysis using cDNAs from tissues obtained at various times after forced weaning of pups identified cathepsin L as up‐regulated during early involution. Levels of cathepsin L mRNA were dramatically increased within 24 hr after weaning. Cathepsin L protein detected by immunoblot was also increased during involution, reaching near maximal levels by 36 hr after weaning. In situ immunohistochemistry detected pronounced cathepsin L protein in the cytoplasm and cell periphery. Mice treated with a specific inhibitor of cathepsin L exhibited substantially reduced numbers of apoptotic cells at times up to 72 hr after weaning when compared with untreated animals. The cathepsin L inhibitor did not alter levels of cathepsin L detected in immunoblots or influence molecular weight of the cathepsin L species detected. These data suggest that cathepsin L plays a regulatory role early in the process of mammary gland involution. Developmental Dynamics 227:315–322, 2003. © 2003 Wiley‐Liss, Inc.