Interactions between cells and collagen V molecules or single chains involve distinct mechanisms

Area of Science:

• Biochemistry
• Cell Biology
• Biomaterials Science

Background:

• Collagen V is a crucial component of the extracellular matrix.
• Understanding collagen-cell interactions is vital for tissue engineering and regenerative medicine.

Purpose of the Study:

• To investigate the cell adhesion-promoting activity of collagen V.
• To elucidate the molecular mechanisms underlying cell attachment to collagen V.

Main Methods:

• Preparation of acid-soluble and pepsin-treated collagen V from human sources.
• Testing cell adhesion and spreading on collagen V using 14 cell lines.
• Investigating the role of collagen V domains, alpha chains, and RGD sequences.
• Utilizing cell adhesion inhibition experiments with synthetic peptides and integrin blocking.

Main Results:

• Ten of 14 cell lines adhered to and spread on collagen V.
• Cell binding sites are primarily within the triple-helical domain.
• Both native and denatured collagen V induced cell adhesion, but via different mechanisms.
• Alpha 2(V) chains were more efficient in cell adhesion than alpha 1(V) chains.
• RGD-independent mechanisms involving alpha 1 beta 1 and alpha 2 beta 1 integrins mediated adhesion to native collagen V.
• RGD-dependent mechanisms mediated adhesion to denatured collagen V.

Conclusions:

• Collagen V acts as a specific adhesive substrate for diverse cell types.
• Distinct RGD-dependent and RGD-independent receptors mediate cell attachment to unfolded and native collagen V, respectively.
• This mechanism is conserved among interstitial collagens, suggesting conformational dependence of RGD sequences for integrin recognition.