SOCS3-microtubule interaction via CLIP-170 and CLASP2 is critical for modulation of endothelial inflammation and lung injury

J Biol Chem. 2021 Jan-Jun:296:100239. doi: 10.1074/jbc.RA120.014232. Epub 2021 Jan 9.

Abstract

Proinflammatory cytokines such as IL-6 induce endothelial cell (EC) barrier disruption and trigger an inflammatory response in part by activating the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. The protein suppressor of cytokine signaling-3 (SOCS3) is a negative regulator of JAK-STAT, but its role in modulation of lung EC barrier dysfunction caused by bacterial pathogens has not been investigated. Using human lung ECs and EC-specific SOCS3 knockout mice, we tested the hypothesis that SOCS3 confers microtubule (MT)-mediated protection against endothelial dysfunction. SOCS3 knockdown in cultured ECs or EC-specific SOCS3 knockout in mice resulted in exacerbated lung injury characterized by increased permeability and inflammation in response to IL-6 or heat-killed Staphylococcus aureus (HKSA). Ectopic expression of SOCS3 attenuated HKSA-induced EC dysfunction, and this effect required assembled MTs. SOCS3 was enriched in the MT fractions, and treatment with HKSA disrupted SOCS3-MT association. We discovered that-in addition to its known partners gp130 and JAK2-SOCS3 interacts with MT plus-end binding proteins CLIP-170 and CLASP2 via its N-terminal domain. The resulting SOCS3-CLIP-170/CLASP2 complex was essential for maximal SOCS3 anti-inflammatory effects. Both IL-6 and HKSA promoted MT disassembly and disrupted SOCS3 interaction with CLIP-170 and CLASP2. Moreover, knockdown of CLIP-170 or CLASP2 impaired SOCS3-JAK2 interaction and abolished the anti-inflammatory effects of SOCS3. Together, these findings demonstrate for the first time an interaction between SOCS3 and CLIP-170/CLASP2 and reveal that this interaction is essential to the protective effects of SOCS3 in lung endothelium.

Keywords: SOCS3; Staphylococcus aureus; cell junction; cytoskeleton; endothelial dysfunction; inflammation; lung injury; microtubule; permeability.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Lung Injury / genetics
  • Acute Lung Injury / microbiology
  • Acute Lung Injury / pathology
  • Animals
  • Cytoskeleton / genetics
  • Endothelial Cells
  • Endothelium, Vascular / metabolism
  • Endothelium, Vascular / microbiology
  • Endothelium, Vascular / pathology
  • Humans
  • Inflammation / genetics*
  • Inflammation / metabolism
  • Inflammation / microbiology
  • Inflammation / pathology
  • Intercellular Junctions / genetics
  • Interleukin-6 / genetics
  • Lung Injury / genetics*
  • Lung Injury / metabolism
  • Lung Injury / microbiology
  • Lung Injury / pathology
  • Mice
  • Mice, Knockout
  • Microtubule-Associated Proteins / genetics*
  • Neoplasm Proteins / genetics*
  • Permeability
  • Staphylococcus aureus / pathogenicity
  • Suppressor of Cytokine Signaling 3 Protein / genetics*

Substances

  • CLASP2 protein, human
  • Interleukin-6
  • Microtubule-Associated Proteins
  • Neoplasm Proteins
  • Suppressor of Cytokine Signaling 3 Protein
  • cytoplasmic linker protein 170