Figure 3.

Regulation of collagen levels in co-cultures of monocytes-derived macrophages (MDM) or alveolar macrophages (AM) and fibroblasts. The bars represent fold change in total (closed bars) or collagenase-sensitive (open bars) metabolic incorporation of ¹⁴C-proline (mean CPM ± SD of quadruplicate cultures). The collagen production was upregulated when fibroblasts were co-cultured with MDM or AM alone and the levels of collagen increased further significantly when MDM have ingested apoptotic cells (Apopt). The levels of collagen did not change in co-cultures of fibroblasts with AM that have ingested apoptotic cells. Significant increases in ¹⁴C-proline incorporation (p < 0.05) are indicated with asterisks.