Instillation of hyaluronan reverses acid instillation injury to the mammalian blood gas barrier

Academic Article


  • Acid (HCl) aspiration during anesthesia may lead to acute lung injury. There is no effective therapy. We hypothesized that HCl instilled intratracheally in C57BL/6 mice results in the formation of low-molecular weight hyaluronan (L-HA), which activates RhoA and Rho kinase (ROCK), causing airway hyperresponsiveness (AHR) and increased permeability. Furthermore, instillation of high-molecular weight hyaluronan (H-HA; Yabro) will reverse lung injury. We instilled HCl in C57BL/6 wild-type (WT), myeloperoxidase gene-deficient (MPO-/-) mice, and CD44 gene-deficient (CD44-/-) mice. WT mice were also instilled intranasally with H-HA (Yabro) at 1 and 23 h post-HCl. All measurements were performed at 1, 5, or 24 h post-HCl. Instillation of HCl in WT but not in CD44-/-resulted in increased inflammation, AHR, lung injury, and L-HA in the bronchoalveolar lavage fluid (BALF) 24 h post-HCl; L-HA levels and lung injury were significantly lower in HCl-instilled MPO-/-mice. Isolated perfused lungs of HCl instilled WT but not of CD44-/-mice had elevated values of the filtration coefficient (Kf). Addition of L-HA on the apical surface of human primary bronchial epithelial cell monolayer decreased barrier resistance (RT). H-HA significantly mitigated inflammation, AHR, and pulmonary vascular leakage at 24 h after HCl instillation and mitigated the increase of Kf and RT, as well as ROCK2 phosphorylation. Increased H- and L-HA levels were found in the BALF of mechanically ventilated patients but not in healthy volunteers. HCl instillation-induced lung injury is mediated by the L-HA-CD44-RhoA-ROCK2 signaling pathway, and H-HA is a potential novel therapeutic agent for acid aspiration-induced lung injury.
  • Digital Object Identifier (doi)

    Author List

  • Zhou T; Yu Z; Jian MY; Ahmad I; Trempus C; Wagener BM; Pittet JF; Aggarwal S; Garantziotis S; Song W
  • Start Page

  • L808
  • End Page

  • L821
  • Volume

  • 314
  • Issue

  • 5