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Published on: July 6, 2019
[Effects of vasoactive intestinal peptide on LPS-induced MMP-9 expression by alveolar macrophages in rats]
Yong-ping Liu1, Cha-xiang Guan, Hong-bo Bai
1Department of Physiology, Xiangya Medical College, Central South University, Changsha 410078, China.
Objective:
To explore the role of vasoactive intestinal peptide (VIP) on LPS-induced MMP-9 expression by alveolar macrophages (AM) in rats.
Methods:
LPS-induced cultured Wistar rats AMs were treated with different concentrations of VIP (10(-10) to approximately 10(-6) mol/L) for 24 h. AMs and the supernatant were collected to measure the MMP-9 expression and activity by RT-PCR and gelatin zymography, respectively. Results The MMP-9 activity and expression of LPS-induced AMs were significantly higher than those in the control group (P < 0.01). VIP (10(-9) to approximately 10(-6) mol/L) down-regulated LPS-induced MMP-9 activity and its expression. The effects were diminished by H-7 and W-7, an antagonist of protein kinase C (PKC) and calmodulin (CaM) (P < 0.01).
Conclusion:
VIP can decrease LPS-induced MMP-9 activity and its expression, which may be related to protein kinase C and calmodulin pathway. VIP may have protective roles in the lung injury.
Insights
Vasoactive intestinal peptide (VIP) reduces lipopolysaccharide (LPS)-induced matrix metalloproteinase-9 (MMP-9) in rat alveolar macrophages. This suggests VIP may protect against lung injury by modulating MMP-9 via protein kinase C and calmodulin pathways.
Area of Science:
- Immunology
- Cell Biology
- Pharmacology
Context:
- Lipopolysaccharide (LPS) triggers inflammatory responses in alveolar macrophages (AMs).
- Matrix metalloproteinase-9 (MMP-9) is implicated in lung injury pathogenesis.
- Vasoactive intestinal peptide (VIP) is a neuropeptide with potential immunomodulatory effects.
Purpose:
- To investigate the effect of VIP on LPS-induced MMP-9 expression and activity in rat AMs.
- To elucidate the signaling pathways involved in VIP's action on MMP-9.
Summary:
- LPS significantly increased MMP-9 activity and expression in rat AMs.
- VIP treatment dose-dependently inhibited LPS-induced MMP-9 activity and expression.
- These inhibitory effects were attenuated by protein kinase C (PKC) and calmodulin (CaM) antagonists (H-7 and W-7).
Impact:
- VIP demonstrates a suppressive role on LPS-induced MMP-9 in AMs.
- The findings suggest that VIP's protective effects in lung injury may involve the PKC and CaM signaling pathways.
- This research highlights VIP as a potential therapeutic agent for inflammatory lung conditions.
