Oxygen-Loaded Nanodroplets Effectively Abrogate Hypoxia Dysregulating Effects on Secretion of MMP-9 and TIMP-1 by
Giulia Rossana Gulino1, Chiara Magnetto2, Amina Khadjavi3
1Dipartimento di Oncologia, Università di Torino, 10126 Torino, Italy.
Abstract:
Monocytes play a key role in the inflammatory stage of the healing process. To allow monocyte migration to injured tissues, the balances between secreted matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) must be finely modulated. However, a reduction of blood supply and local oxygen tension can modify the phenotype of immune cells. Intriguingly, hypoxia might be targeted by new effective oxygenating devices such as 2H,3H-decafluoropentane- (DFP-) based oxygen-loaded nanodroplets (OLNs). Here, hypoxia effects on gelatinase/TIMP release from human peripheral monocytes were investigated, and the therapeutic potential of dextran-shelled OLNs was evaluated. Normoxic monocytes constitutively released ~500 ng/mL MMP-9, ~1.3 ng/mL TIMP-1, and ~0.6 ng/mL TIMP-2 proteins. MMP-2 was not detected. After 24 hours, hypoxia significantly altered MMP-9/TIMP-1 balance by reducing MMP-9 and increasing TIMP-1, without affecting TIMP-2 secretion. Interestingly OLNs, not displaying toxicity to human monocytes after cell internalization, effectively counteracted hypoxia, restoring a normoxia-like MMP-9/TIMP-1 ratio. The action of OLNs was specifically dependent on time-sustained oxygen diffusion up to 24 h from their DFP-based core. Therefore, OLNs appear as innovative, nonconventional, cost-effective, and nontoxic therapeutic tools, to be potentially employed to restore the physiological invasive phenotype of immune cells in hypoxia-associated inflammation.
Insights
Hypoxia disrupts monocyte function by altering matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) release. Oxygen-loaded nanodroplets (OLNs) effectively restored normal monocyte function, showing therapeutic potential for inflammation.
Area of Science:
- Biomedical Engineering
- Immunology
- Wound Healing Research
Background:
- Monocytes are crucial for inflammation during healing, requiring balanced matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) for migration.
- Reduced oxygen (hypoxia) can alter immune cell function, potentially impairing the healing process.
- 2H,3H-decafluoropentane- (DFP-) based oxygen-loaded nanodroplets (OLNs) are novel oxygenating devices.
Purpose of the Study:
- To investigate the effects of hypoxia on gelatinase/TIMP release from human peripheral monocytes.
- To evaluate the therapeutic potential of dextran-shelled OLNs in counteracting hypoxia-induced changes in monocytes.
Main Methods:
- Human peripheral monocytes were cultured under normoxic and hypoxic conditions.
- MMP-9, TIMP-1, and TIMP-2 protein levels were quantified using ELISA.
- The effects of OLNs on monocyte phenotype and protein release under hypoxia were assessed.
- Monocyte toxicity of OLNs was evaluated post-internalization.
Main Results:
- Normoxic monocytes released significant amounts of MMP-9, TIMP-1, and TIMP-2.
- Hypoxia significantly reduced MMP-9 and increased TIMP-1, disrupting the MMP-9/TIMP-1 balance.
- Internalized OLNs demonstrated no toxicity to human monocytes.
- OLNs effectively counteracted hypoxia, restoring a normoxia-like MMP-9/TIMP-1 ratio through sustained oxygen release.
Conclusions:
- Hypoxia alters the critical MMP-9/TIMP-1 balance in monocytes, potentially hindering tissue repair.
- Dextran-shelled OLNs are non-toxic and effectively restore normoxia-like monocyte function.
- OLNs represent a promising therapeutic strategy for managing hypoxia-associated inflammation by normalizing immune cell phenotype.
