Down-regulation of KLF2 in lung fibroblasts is linked with COVID-19 immunofibrosis and restored by combined inhibition of NETs, JAK-1/2 and IL-6 signaling

Akrivi Chrysanthopoulou; Christina Antoniadou; Anastasia-Maria Natsi; Efstratios Gavriilidis; Vasileios Papadopoulos; Evangelia Xingi; Stylianos Didaskalou; Dimitrios Mikroulis; Victoria Tsironidou; Konstantinos Kambas; Maria Koffa; Panagiotis Skendros; Konstantinos Ritis

doi:10.1016/j.clim.2023.109240

Down-regulation of KLF2 in lung fibroblasts is linked with COVID-19 immunofibrosis and restored by combined inhibition of NETs, JAK-1/2 and IL-6 signaling

Clin Immunol. 2023 Feb:247:109240. doi: 10.1016/j.clim.2023.109240. Epub 2023 Jan 21.

Affiliations

¹ Laboratory of Molecular Hematology, Department of Medicine, Democritus University of Thrace, Alexandroupolis, Greece.
² First Department of Internal Medicine, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece.
³ Light Microscopy Unit, Hellenic Pasteur Institute, Athens, Greece.
⁴ Laboratory of Cell Biology, Proteomics and Cell Cycle, Department of Molecular Biology and Genetics, Democritus University of Thrace, Alexandroupolis, Greece.
⁵ Department of Cardiovascular Surgery, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece.
⁶ Laboratory of Molecular Genetics, Department of Immunology, Hellenic Pasteur Institute, Athens, Greece.
⁷ Laboratory of Molecular Hematology, Department of Medicine, Democritus University of Thrace, Alexandroupolis, Greece; First Department of Internal Medicine, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece. Electronic address: pskendro@med.duth.gr.
⁸ Laboratory of Molecular Hematology, Department of Medicine, Democritus University of Thrace, Alexandroupolis, Greece; First Department of Internal Medicine, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece. Electronic address: kritis@med.duth.gr.

Abstract

Kruppel-like factor 2 (KLF2) has been linked with fibrosis and neutrophil-associated thromboinflammation; however, its role in COVID-19 remains elusive. We investigated the effect of disease microenvironment on the fibrotic potential of human lung fibroblasts (LFs) and its association with KLF2 expression. LFs stimulated with plasma from severe COVID-19 patients down-regulated KLF2 expression at mRNA/protein and functional level acquiring a pre-fibrotic phenotype, as indicated by increased CCN2/collagen levels. Pre-incubation with the COMBI-treatment-agents (DNase I and JAKs/IL-6 inhibitors baricitinib/tocilizumab) restored KLF2 levels of LFs to normal abolishing their fibrotic activity. LFs stimulated with plasma from COMBI-treated patients at day-7 expressed lower CCN2 and higher KLF2 levels, compared to plasma prior-to-treatment, an effect not observed in standard-of-care treatment. In line with this, COMBI-treated patients had better outcome than standard-of-care group. These data link fibroblast KLF2 with NETosis and JAK/IL-6 signaling, suggesting the potential of combined therapeutic strategies in immunofibrotic diseases, such as COVID-19.

Keywords: Baricitinib; COVID-19; DNase I; Immunofibrosis; KLF2; Tocilizumab.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

COVID-19*
Down-Regulation
Fibroblasts / metabolism
Fibrosis
Humans
Inflammation
Interleukin-6 / metabolism
Kruppel-Like Transcription Factors* / genetics
Kruppel-Like Transcription Factors* / metabolism
Lung / metabolism
Thrombosis*
Transcription Factors / genetics

Substances

Interleukin-6
KLF2 protein, human
Kruppel-Like Transcription Factors
Transcription Factors