Stromal-Epithelial Interactions during Mammary Gland Development

Abstract

Mammary gland is an organ, which undergoes the majority of its development in the postnatal life of mammals. The complex structure of the mammary gland comprises epithelial and myoepithelial cells forming the parenchymal tissue and adipocytes, fibroblasts, vascular endothelial cells, and infiltrating immune cell composing the stromal compartment. During puberty and in adulthood, circulating hormones released from the pituitary and ovaries regulate the rate of development and functional differentiation of the mammary epithelium. In addition, growing body of evidence shows that interactions between the stromal and parenchymal compartments of the mammary gland play a crucial role in mammogenesis. This regulation takes place on a paracrine level, by locally synthesized growth factors, adipokines, and cytokines, as well as via direct cell-cell interactions. This chapter summarizes the current knowledge about the complex nature of interactions between the mammary epithelium and stroma during mammary gland development in different mammalian species.

Reshaping in vitro Models of Breast Tissue: Integration of Stromal and Parenchymal Compartments in 3D Printed Hydrogels

“…The metabolic activity of fibroblasts decreased from day 1 to day 4, which was mainly attributed to initial cell loss, and then attained nearly steady values. This was somehow expected, as in the mammary gland, fibroblasts are typically in a relatively quiescent state, proliferating slowly and remodeling their ECM (Dziegelewska and Gajewska, 2018). In our model, multiple protein components commonly found in native ECM were endogenously produced by seeded hMF, suggesting the establishment of an ECM-rich stromal niche.…”

“…In the mammary gland, complex interactions between the epithelium and different other cell types direct the progression of normal mammary gland morphogenesis, being also implicated in pathological events (Dziegelewska and Gajewska, 2018). For instance, the interplay between the immune system and tumor progression is well-recognized, and a variety of pro-and antitumor immune cells can modulate the outcome toward tumor growth and progression or immune rejection (Zhu et al, 2019).…”

“…The second stage of this work was the establishment of the stromal compartment, where human mammary fibroblasts were seeded onto 3D printed porous scaffolds. Fibroblasts, together with adipocytes, are major cellular components of the mammary stroma, playing a key regulatory role in the mammary gland pathophysiology, not only by providing ECM-cues, but also by secreting bioactive compounds (Dziegelewska and Gajewska, 2018). Also, fibroblasts are the most abundant stromal cell type in epithelial tumors (Kalluri, 2016).…”

A comprehensive survey on optimal components of extracellular matrix for kidney development and function

“…Wnt4 prevents UB branching and tubulogenesis with deprivation of GAG chains [28][29][30]. The breakdown of ECM can also lead to activation of important signaling molecules such as Areg, Wnts, TGF and FGF, which affect branching [31]. TGF can bind to various integrins and other ECM molecules like fi brillin, vitronectin and FN, some when this action occurs via heparin sulfate [32] TGF signaling may be regulate the affi nity of integrins for relevant ECM binding.…”

TMT based deep proteome analysis of buffalo mammary epithelial cells and identification of novel protein signatures during lactogenic differentiation

“…Differentiation is a significant event during late pregnancy of the mammary gland development, that results in MECs with the ability to synthesize milk. Differentiation of MECs is characterized by molecular 12 and morphological changes 13 . Differentiated MECs are polarized in nature and secrete milk proteins such as β‐casein (CSN2) and α‐lactalbumin (LALBA) 14 .…”