Basement membrane | EPFL Graph Search

The basement membrane, also known as base membrane is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tissues including mesothelium and endothelium, and the underlying connective tissue. As seen with the electron microscope, the basement membrane is composed of two layers, the basal lamina and the reticular lamina. The underlying connective tissue attaches to the basal lamina with collagen VII anchoring fibrils and fibrillin microfibrils. The basal lamina layer can further be subdivided into two layers based on their visual appearance in electron microscopy. The lighter-colored layer closer to the epithelium is called the lamina lucida, while the denser-colored layer closer to the connective tissue is called the lamina densa. The electron-dense lamina densa layer is about 30–70 nanometers thick and consists of an underlying network of reticular collagen IV fibrils which average 30 nanometers in diameter and 0.1–2 micrometers in thickness and are coated with the heparan sulfate-rich proteoglycan perlecan. In addition to collagen, this supportive matrix contains intrinsic macromolecular components. The lamina lucida layer is made up of laminin, integrins, entactins, and dystroglycans. Integrins are a key component of hemidesmosomes which serve to anchor the epithelium to the underlying basement membrane. To represent the above in a visually organised manner, the basement membrane is organized as follows: Epithelial/mesothelial/endothelial tissue (outer layer) Basement membrane Basal lamina Lamina lucida laminin integrins (hemidesmosomes) nidogens dystroglycans Lamina densa collagen IV (coated with perlecan, rich in heparan sulfate) Attaching proteins (between the basal and reticular laminae) collagen VII (anchoring fibrils) fibrillin (microfibrils) Lamina reticularis collagen III (as reticular fibers) Connective tissue (Lamina propria) The primary function of the basement membrane is to anchor down the epithelium to its loose connective tissue (the dermis or lamina propria) underneath.

Mechanical Properties of Soft Biological Membranes for Organ-on-a-Chip Assessed by Bulge Test and AFM

Georg Fantner, Johann Michler, Veronika Cencen

Advanced in vitro models called “organ-on-a-chip” can mimic the specific cellular environment found in various tissues. Many of these models include a thin, sometimes flexible, membrane aimed at mimicking the extracellular matrix (ECM) scaffold of in vivo ...

2021

The secreted protease Adamts18 links hormone action to activation of the mammary stem cell niche

Cathrin Brisken, Giovanna Ambrosini, Marian Caikovski, Philipp Bucher, Renuga Devi Rajaram, Patrik Aouad, Dalya Ataca, Marie Shamseddin, Céline Berthe Constantin, Csaba Ferenc László

Estrogens and progesterone control breast development and carcinogenesis via their cognate receptors expressed in a subset of luminal cells in the mammary epithelium. How they control the extracellular matrix, important to breast physiology and tumorigenes ...

2020

90 YEARS OF PROGESTERONE Progesterone receptor signaling in the normal breast and its implications for cancer

Cathrin Brisken, Valentina Scabia

Progesterone is considered as the pregnancy hormone and acts on many different target tissues. Progesterone receptor (PR) signaling is important for normal development and the physiologic function of the breast and impinges on breast carcinogenesis. Both s ...

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