File:Mammary involution.jpg

From Embryology

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Mammary Gland - Signalling Events in Involution

  1. Milk stasis induces the expression of leukaemia inhibitory factor (LIF) and transforming growth factor (TGF)β3 within 12 hours of forced weaning.
  2. These, in turn, phosphorylate and activate the transcription factor Stat3.
  3. This results in the induction of apoptosis and shedding of dying cells into the alveolar lumen.
  4. Neighbouring cells migrate to close the gap and maintain the integrity of the alveolar structure.
  1. Concurrently with these events, members of the death receptor ligand family and their receptors are transcriptionally upregulated and this induces apoptosis through activation of caspase 8.
  2. Downstream targets of these pathways are then induced and ensure the transition to the second phase.
  3. Following this reversible first phase, matrix metalloproteases (MMP) begin to break down the ECM surrounding each alveolus, resulting in detachment induced apoptosis and collapse of the alveoli.
  4. Remodelling is then completed by re-differentiation of the adipoctyes which requires the action of plasmin and MMP3.

Full involution returns the gland to a pre-pregnant state. ECM, extracellular matrix.


Links: mammary gland | apoptosis

Reference

Watson CJ. (2006). Involution: apoptosis and tissue remodelling that convert the mammary gland from milk factory to a quiescent organ. Breast Cancer Res. , 8, 203. PMID: 16677411 DOI.

Breast Cancer Res. 2006; 8(2): 203. Published online 2006 April 10. doi: 10.1186/bcr1401.

Copyright

© 2006 BioMed Central Ltd

Illustrations, figures or tables from research articles may be reproduced in any format or medium, provided that BioMed Central is duly identified as the original publisher, and that proper attribution of authorship and correct citation details are given, in accordance with BioMed Central's Open Access Charter.


Involution: apoptosis and tissue remodelling that convert the mammary gland from milk factory to a quiescent organ. Watson CJ. Breast Cancer Res. 2006;8(2):203. Epub 2006 Apr 10. Review. PMID 16677411


Cite this page: Hill, M.A. (2024, June 21) Embryology Mammary involution.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Mammary_involution.jpg

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G

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current16:21, 10 May 2012Thumbnail for version as of 16:21, 10 May 2012600 × 427 (54 KB)Z8600021 (talk | contribs)==Mammary Gland - Signalling Events in Involution== # Milk stasis induces the expression of leukaemia inhibitory factor (LIF) and transforming growth factor (TGF)β3 within 12 hours of forced weaning. # These, in turn, phosphorylate and activate the tra