Effects of extracellular matrix proteins on macrophage differentiation, growth, and function: Comparison of liquid and agar culture systems

Abstract

Both spaceflight and skeletal unloading suppress the haematopoietic differentiation of macrophages (Sonnenfeld et al., Aviat. Space Environ. Med., 61:648-653, 1990; Armstrong et al., J. Appl. Physiol., 75:2734-2739, 1993). The mechanism behind this reduction in haematopoiesis has yet to be elucidated. However, changes in bone marrow extracellular matrix (ECM) may be involved. To further understand the role of ECM products in macrophage differentiation, we have performed experiments evaluating the effects of fibronectin, laminin, collagen type I, and collagen type IV on macrophage development and function. Bone marrow-derived macrophages cultured on four different ECM substrates in liquid culture medium showed less growth than those cultured on plastic. Significant morphological differences were seen on each of the substrates used. Phenotypically and functionally, as measured by class II major histocompatibility molecule (MHCII) expression, MAC-2 expression, and the secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), these macrophages were similar. In contrast, bone marrow-derived macrophages cultured in suspension, using agar, showed no difference in growth when exposed to ECM proteins. However, IL-6 and TNF-alpha secretion was affected by fibronectin, laminin, collagen type I, and collagen type IV in a concentration-dependent manner. We conclude that the ECM products fibronectin, laminin, collagen type I, and collagen type IV have profound effects on macrophage development and function. Additionally, we suggest that an ECM-supplemented agar culture system provides an environment more analogous to in vivo bone marrow than does a traditional liquid culture system.

Changes on lysosomal compartment during PMA-induced differentiation of THP-1 monocytic cells: Influence of type I and type IV collagens

“…This is in agreement with the evidence, in several tissues, of the role of extracellular matrix components (fibronectin, laminin, type I and IV collagens, etc.) in modulating in situ the processes of macrophagic differentiation and activation [37,38]. Our findings indicated that, between the two types of collagen, the higher effects on cytodifferentiation and activation are observed in the presence of type I collagen with respect to type IV collagen.…”

Biophysical regulation of macrophages in health and disease

“…Although ECM coatings on two‐dimensional (2D) culture surfaces provide some insight to the effect of composition on macrophage function, it poorly recapitulates the three‐dimensional (3D) environment that cells experience in the body. In the same early study described above, BMDMs were cultured in agar suspensions containing ECM proteins, IL‐6 secretion was significantly reduced compared to control agar with no ECM protein, suggesting that adhesion to the matrix in a 3D environment modulates macrophage cytokine secretion. Our laboratory observed that macrophages cultured on top of fibrin gels generated by polymerization of fibrinogen using thrombin, exhibit reduced secretion of TNFα when compared to cells cultured on polystyrene surfaces .…”

“…To investigate the effects of ECM composition on macrophages, cells can be cultured on surfaces coated with various ECM proteins, and their behavior examined. In an early study, bone marrow‐derived macrophages (BMDMs) cultured on dishes coated with fibronectin, laminin, type I collagen or type IV collagen were found to have a slower growth rate when compared to cells cultured on tissue culture plastic alone, which naturally adsorbs soluble ECM proteins found in serum . Cells adopted different morphologies on different ECMs, with collagen IV and laminin causing a rounder shape, compared to the other ECMs.…”

“…In an early study, bone marrow-derived macrophages (BMDMs) cultured on dishes coated with fibronectin, laminin, type I collagen or type IV collagen were found to have a slower growth rate when compared to cells cultured on tissue culture plastic alone, which naturally adsorbs soluble ECM proteins found in serum. 19 Cells adopted different morphologies on different ECMs, with collagen IV and laminin causing a rounder shape, compared to the other ECMs. Despite clear changes in morphology, secretion of inflammatory cytokines including IL-6 and TNF was similar across the different culture conditions.…”

Role of soluble factors and three-dimensional culture inin vitrodifferentiation of intestinal macrophages

“…It was reported that ECM also plays a role in the differentiation of embryonic stem cells [35] and skeletal muscle cells [36] . Armstrong et al [37] have shown that ECM proteins have effects on MAC differentiation, growth and function.…”