extracellular matrix Flashcards
What are the two main types of tissue organization in animals?
epithelial tissues
connective tissues
What is the basal lamina, and where is it found?
a thin dense ECM layer found beneath epithelial tissues around muscles and neurones
List three functions of the ECM in tissues
Provides structural integrity and mechanical properties.
Acts as a scaffold for cell organization and attachment.
Regulates cell survival, migration, and proliferation.
What are the two main types of ECM macromolecules?
proteoglycans and fibrous proteins
Name three types of Glycosaminoglycans and their properties
Hyaluronan: Long, non-sulfated, creates hydrated gels.
Heparan Sulfate: Binds growth factors, involved in signaling.
Chondroitin Sulfate: Contributes to structural integrity in cartilage.
What are proteoglycans, and provide an example?
core proteins that are covalently linked to glycosaminoglycans
aggercans in cartilage provides compressive strength
What is the primary structural unit of collagen?
triple helix with 3 alpha chains and Gly-XY sequence
How is collagen organized in connective tissues?
procollagen cleaved into fibrils then cross-linked into fibres to provide tensile strength
What is elastin, and where is it found?
a fibrous protein that provides elasticity to skin, lungs and blood vessels
What is fibronectin, and what is its role?
dimeric glycoprotein that binds to integrins and other ECM proteins
help attach cells to ECM by forming insoluble fibrils under tension
What is laminin, and where is it primarily found?
heterodimeric glycoproteins found in basal lamina
act as scaffolding and provides binding sites for ECM components
What enzymes are involved in ECM degradation?
MMPs and serine proteases
what do MMPs do
degrade collagen and other ECM proteins
what does serine proteases do
Activate plasminogen to aid ECM breakdown.
Why is ECM remodeling important?
allows tissue development, wound healing, immune cell migration and tumour metastasis
Name two diseases caused by ECM dysfunction and their associated defects.
Ehlers-danlos syndrome= defective collagen
marfans = fibrilin mutation
How can ECM-targeting therapies be applied?
inhibiting MMPs to prevent cancer metastasis
What are the key components of the basal lamina?
laminin, collagen IV, nidogen, perlecan
List three roles of the basal lamina.
Provides physical support to epithelial layers.
Acts as a filtration barrier (e.g., in kidney glomeruli).
Guides tissue regeneration and cell polarity.
Which receptor mediates cell-ECM adhesion, and what is its role?
integrins
ECM proteins to cytoskeleton
mediate signalling pathways
How does the ECM regulate cell behavior?
By influencing shape, polarity, differentiation, migration, and survival through signaling pathways.
