Fig. 3
From: Surfactant protein D and bronchopulmonary dysplasia: a new way to approach an old problem
Surfactant protein D (SP-D) mechanisms to counteract BPD inducing factors. SP-D antimicrobial and anti-inflammatory activities could prevent the alveolar damage induced by chorioamnionitis. SP-D contributes to surfactant stability and homeostasis, actions that in combination with its anti-inflammatory action could help to prevent the damage caused by mechanical ventilation and oxygen therapy. SP-D inhibits viral replication, opsonizes and induces aggregation of invading pathogens in secondary lung infections and sepsis to boost their clearance, which is also translated in decreased inflammation. Administration of exogenous SP-D could replenish lung SP-D deficient levels in the preterm lungs and provide oligomerized active SP-D. Last, SP-D could protect the lung from the effects of hyperoxia by inhibiting the recruitment of inflammatory cells, regulating reactive oxygen species (ROS) metabolism, attenuating NETosis, and therefore, decreasing inflammation