TNF and acute respiratory distress syndrome: Interestingly, exposure of cultured human lung fibroblasts to TNFα or bronchoalveolar lavage fluid (BALF) from ARDS patients induced the expression of membrane type-1 metalloproteinase (MT1-MMP) leading to increased shedding of LRP1, whereas the presence of a blocking antibody against TNFα reduced sLRP1 levels in the conditioned medium (64).