Collagen matrix as a tool in studying fibroblastic cell behavior

Abstract

Type I collagen is a fibrillar protein, a member of a large family of collagen proteins. It is present in most body tissues, usually in combination with other collagens and other components of extracellular matrix. Its synthesis is increased in various pathological situations, in healing wounds, in fibrotic tissues and in many tumors. After extraction from collagen-rich tissues it is widely used in studies of cell behavior, especially those of fibroblasts and myofibroblasts. Cells cultured in a classical way, on planar plastic dishes, lack the third dimension that is characteristic of body tissues. Collagen I forms gel at neutral pH and may become a basis of a 3D matrix that better mimics conditions in tissue than plastic dishes.

Keywords: 3-dimensional; TGFβ-1; AP-1; activator protein 1; ECM; c-Jun N-terminal kinase; MFB; cell culture; cell proliferation; collagen; extracellular matrix; extracellular matrix; ERK; extracellular signal-regulated kinase; FAK; fibroblasts; fibronectin; focal adhesion kinase; GT; granulation tissue; HSC; hepatic stellate cells; JNK; integrins; megakaryoblastic leukemia 1; MMP; metalloproteinases; metalloproteinases; NF-κB; myofibroblasts; myofibroblasts; MKL1; nuclear factor kappa B; PI3K/Akt; phosphatidylinositide 3-kinase/Ak strain transforming; PEG; polyethylene glycol; α-SMA; substrate stiffness; tissue inhibitor of metalloproteinases; TNF-α; transforming growth factor β 1; TIMP; tumor necrosis factor α; α-smooth muscle actin; 3D.

Figure 1.

Rat liver myofibroblasts on plastic. Rat liver MFB were cultured on a plastic dish. (A) Cells 1 h, (B) 4 h and (C) 24 h after plating. The cells were initially rounded and then spread on the hard surface (Peterová and Kanta, unpublished results).

Figure 2.

Rat liver myofibroblasts on attached collagen gel. Rat liver MFB were cultured on type I collagen gel. Cells (A) 1 h, (B) 2 h and (C) 24 h after seeding on the gel. The cells were rounded at first but they soon became stellate and aggregated. The gel was detached from the walls and the bottom of the dish 24 h after seeding the cells and the cells were allowed to grow for another 24 h (D) (Peterová and Kanta, unpublished results).

Figure 3.

Rat liver myofibroblasts on stress-released collagen gel. Rat liver MFB were seeded on type I collagen gel. The gel was detached from the walls and the bottom of the dish 1 h later. The cells were still rounded 1 h after release (A), began to elongate after 2 h (B) and acquired a slender shape 24 h after release (C) (Peterová and Kanta, unpublished results).