IL-1 and TNF-α decreased cell proliferation at the tissue surface. (A) Schematic of a meniscal repair explant, indicating the surface of the tissue that was analyzed in pink. Representative confocal images of the surface of (B) inner or (C) outer zone meniscal repair explants that were treated with 0, 10 ng/mL IL-1, 10 ng/mL TNF-α, or 10 ng/mL TGF-β1 for 14 days. In the confocal images, cells that have proliferated are yellow and all cells are labeled red. The scale bar is equal to 100 μm. Inner and outer zone explants were treated with control media and (D) 10 ng/mL IL-1, (E) 10 ng/mL TNF-α, or (F) 10 ng/mL TGF-β1 for 14 days. The data are graphed as a percentage of proliferated cells at the surface of the tissue + standard error. *: P < 0.00005 compared to control.