Effect of cyclic strain and plating matrix on cell proliferation and integrin expression by ligament fibroblasts

Abstract

The role of cell surface integrins in cell migration, proliferation, and attachment to matrix molecules is well known. Integrin-matrix interactions have been implicated in mechanotransduction and load transmission from the outside to the inside of the cell. In this study, the effect of cyclic strain on the cell proliferation, attachment, and expression of integrin subunits b1, b3, and a5 was determined in anterior cruciate ligament (ACL) and medial collateral ligament (MCL) fibroblasts grown on polystyrene, Type I collagen, laminin, elastin, and fibronectin. ACL fibroblast proliferation was not affected by growth substrate whereas MCL cells reached confluence more rapidly on fibronectin compared with collagen or polystyrene. Exposure to 5% cyclic strain resulted in a significant decrease in ACL and MCL fibroblast proliferation on fibronectin and Type I collagen. MCL cells showed a greater strain-dependent inhibition of cells grown on a fibronectin substrate than those grown on collagen. This matrix-dependent effect of strain on cell proliferation was not seen with ACL cells. Attachment of ACL and MCL fibroblasts was stronger to fibronectin compared with Type I collagen, laminin, and polystyrene. In the absence of applied load, the expression of b1, b3, and a5 subunits was not substrate dependent and the expression of b1 and a5 integrin subunits was higher in MCL cells than ACL cells on all substrates. In contrast, the expression of b3 integrin subunit was higher in ACL cells than MCL cells. In response to 5% strain, b1, and a5 expression increased in all fibroblasts with MCL cells having a higher magnitude of expression. b3 expression showed a 90% increase in response to load when grown on laminin for both MCL and ACL fibroblasts and demonstrated no change in expression on Type I collagen or fibronectin. The duration of applied strain from 2 versus 22 h had no effect on cell proliferation or integrin expression. ß

Influence of stress on extracellular matrix and integrin biology

“…Thus, compared with 2D culture, 3D culture resulted in increased expression of a5b1 in fibroblasts and chondrocytes (Takahashi et al, 2003;Hannafin et al, 2006), b1 subunit in gliomas and breast cancer cells, or a6 in chondrosarcoma (Demou, 2010).…”

Design and Performance of an Optically Accessible, Low-Volume, Mechanobioreactor for Long-Term Study of Living Constructs

“…In vertebrate animals, there is substantial and long-established evidence that properly applied mechanical forces are necessary for the appropriate growth, maintenance, and remodeling of musculoskeletal system components. 2,[5][6][7][8][9][10] While there has been a significant research effort focused on mechanobiology of the extracellular matrix, [10][11][12][13][14][15][16][17][18][19][20] there is no consensus on how even the simplest connective tissue structures are initially formed, grown, and maintained. 21,22 Nonetheless, it has been recognized that the mechanical state of a tissue is a potent regulator of (i) fibroblast differentiation state, (ii) migration direction/speed, and (iii) the local secretome.…”

Effect of mechanical tension on the human dental pulp cells

“…After 6 and 24 h, increased proliferation was observed following a period of 15 and 60 min of stretching. Furthermore, there have been some reports where an appropriate level of mechanical force was shown to stimulate or inhibit cell proliferation [48][49][50][51][52][53][54][55]. Kaspar et al [56] reported an increase in human osteoblastic cell proliferation and type I collagen propeptide release under mechanical strain (1,000 μ strain, 1 Hz, 30 min/day, for 2 days).…”