TNF and edema: When the body stimulated by LPS, the activated macrophages will release a large number of pro-inflammatory cytokines such as TNF-α, IL-6 and IL-1β, which further induce neutrophils to migrate, aggregate in the interstitial and alveolar cavity, and produce respiratory bursts after the activation of aggregated neutrophils, leading to lung-lung eruption, and a series of lung tissue injuries, such as vascular congestion, pulmonary edema, alveolar atrophy, etc. [7, 29].