Using Nkx2.5 to interfere with profibrotic mechanotransduction signaling to prevent further fibrotic progression in IPF

Introduction: Idiopathic pulmonary fibrosis (IPF) is a life-threatening interstitial lung disease with limited treatment options that is caused by excessive deposition of extracellular matrix components. Recent work has linked the profibrotic activity seen in IPF to the mechanotransduction pathway. Homeobox protein Nkx2.5, a transcription factor that has been identified as a mechanosensitive repressor of α-smooth muscle actin expression, is antagonistic to this process. Aims: We aim to characterize Nkx2.5 expression and assess changes in myofibroblast differentiation in various environmental models and conditions. Methods: Baseline Nkx2.5 expression in the lung was quantified using primary human lung fibroblasts (PHLF) from nonfibrotic and fibrotic sources grown in soft and stiff cell culture plates. A lentiviral overexpression system will be used in PHLFs to determine if transition to profibrotic phenotypes can be prevented, and normal function can be restored. Expression of α-smooth muscle actin and extra cellular matrix protein collagen was measured to quantify fibrosis progression and assess the efficacy of Nkx2.5 as a repressor of fibrosis. Results: Immunostaining shows a reduction in the amount of Nkx2.5 in IPF lung compared to the healthy control. Preliminary work showed that fibroblasts grown in the soft environments had significantly higher amounts of Nkx2.5 when compared to the rigid environments. Conclusions: This research points to a new potential therapeutic target for IPF, allowing for more diverse treatment strategies as restoring proteins involved in normal, non-pathogenic function can help to complement current intervention.