Protective effects of GHK-Cu in bleomycin-induced pulmonary fibrosis via anti-oxidative stress and anti-inflammation pathways

Life Sci. 2020 Jan 15:241:117139. doi: 10.1016/j.lfs.2019.117139. Epub 2019 Dec 4.


Background: Idiopathic pulmonary fibrosis (IPF) is a serious lung problem with advancing and diffusive pulmonary fibrosis as the pathologic basis, and with oxidative stress and inflammation as the key pathogenesis. Glycyl-L-histidyl-l-lysine (GHK) is a tripeptide participating into wound healing and regeneration. GHK-Cu complexes improve GHK bioavailability. Thus, the current study aimed to explore the therapeutic role of GHK-Cu on bleomycin (BLM)-induced pulmonary fibrosis in a mouse model.

Methods: BLM (3 mg/kg) was administered via tracheal instillation (TI) to induce a pulmonary fibrosis model in C57BL/6j mice 21 days after the challenge of BLM. GHK-Cu was injected intraperitoneally (i.p.) at different dosage of 0.2, 2 and 20 μg/g/day in 0.5 ml PBS on alternate day. The histological changes, inflammation response, the collagen deposition and epithelial-mesenchymal transition (EMT) was evaluated in the lung tissue. EMT was evaluated by ɑ-SMA and fibronectin expression in the lung tissue. NF-κB p65, Nrf2 and TGFβ1/Smad2/3 signalling pathways were detected by immunoblotting analysis.

Results: GHK-Cu complex inhibited BLM-induced inflammatory and fibrotic pathological changes, alleviated the inflammatory response in the BALF by reducing the levels of the inflammatory cytokines, TNF-ɑ and IL-6 and the activity of MPO as well as reduced collagen deposition. In addition, the GHK-Cu treatment significantly reversed the MMP-9/TIMP-1 imbalance and partially prevented EMT via Nrf2, NF-κB and TGFβ1 pathways, as well as Smad2/3 phosphorylation.

Conclusions: GHK-Cu presented a protective effect in BLM-induced inflammation and oxidative stress by inhibiting EMT progression and suppressing TGFβ1/Smad2/3 signalling in pulmonary fibrosis.

Keywords: Epithelial-mesenchymal transition; GHK-Cu; Nuclear factor (NF)-κB; Nuclear factor erythroid-related factor 2; Pulmonary fibrosis; Smad; Transforming growth factor beta1.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / pharmacology*
  • Antibiotics, Antineoplastic / toxicity
  • Antioxidants / pharmacology*
  • Bleomycin / toxicity*
  • Collagen / metabolism
  • Copper / administration & dosage*
  • Copper / chemistry
  • Cytokines / metabolism
  • Disease Models, Animal
  • Epithelial-Mesenchymal Transition / drug effects
  • Inflammation / drug therapy
  • Inflammation / immunology
  • Inflammation / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Oligopeptides / administration & dosage*
  • Oligopeptides / chemistry
  • Oxidative Stress / drug effects
  • Pulmonary Fibrosis / chemically induced
  • Pulmonary Fibrosis / metabolism
  • Pulmonary Fibrosis / pathology
  • Pulmonary Fibrosis / prevention & control*
  • Signal Transduction / drug effects*


  • Anti-Inflammatory Agents
  • Antibiotics, Antineoplastic
  • Antioxidants
  • Cytokines
  • Oligopeptides
  • Bleomycin
  • glycyl-histidyl-lysine
  • Copper
  • Collagen