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Updated: Feb 13, 2026

Intraductal Injection for Localized Drug Delivery to the Mouse Mammary Gland
Published on: October 4, 2013
The cJUN NH2-terminal kinase (JNK) pathway contributes to mouse mammary gland remodeling during involution
Nomeda Girnius1, Yvonne J K Edwards1, Roger J Davis2,3
1Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA.
Abstract:
Involution returns the lactating mammary gland to a quiescent state after weaning. The mechanism of involution involves collapse of the mammary epithelial cell compartment. To test whether the cJUN NH2-terminal kinase (JNK) signal transduction pathway contributes to involution, we established mice with JNK deficiency in the mammary epithelium. We found that JNK is required for efficient involution. JNK deficiency did not alter the STAT3/5 or SMAD2/3 signaling pathways that have been previously implicated in this process. Nevertheless, JNK promotes the expression of genes that drive involution, including matrix metalloproteases, cathepsins, and BH3-only proteins. These data demonstrate that JNK has a key role in mammary gland involution post lactation.
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